In this study, the influence of calcium chloride in early hydration reaction of alite was discussed from the results of various experiments conducted by solid phase analysis（XRD・Rietveld analysis and ²⁹Si MAS NMR）and liquid phase analysis（pH meter, ICP-AES and ion chromatography）. In addition, similar experiments were carried out for sodium chloride and Portlandite addition systems, and the results were compared and examined with calcium chloride addition system. As a result, it was confirmed that promotion of initial hydration reaction of alite by addition of calcium chloride was not promoted dissolution of silica due to pH rise. Moreover, in the calcium chloride addition system, the amount of calcium silicate hydrate, the hydrated silicate monomer layer thickness, and the degree of alite hydration remarkably increased after the start of calcium silicate hydrate production. It was also confirmed that in the same addition system, the chloride ion concentration in the liquid phase decreased before the start of calcium silicate hydrate production and that the calcium ion concentration in the liquid phase was larger than that of other addition system and no addition systems. These findings suggested that both chloride ions and calcium ions are affected by accelerating the initial hydration reaction of alite by addition of calcium chloride.

In order to develop fly ash cement（type B）with equal strength to ordinary Portland cement（OPC）, a specific base cement was made. This cement had higher alite and f.CaO content, surface area compared to OPC, and contained different limestone powders. Fly ash cement made with base cement containing 5％ limestone powder was tested over 91 days（at 5℃, 20℃ and 30℃）and developed 92％ of the strength of OPC. As well, it was observed that this strength increasing effect of limestone powder was larger at 5℃ compared 20℃ and 30℃. The fly ash cement that was made also showed a setting time between regular cement and OPC. However, this was considered to be a result of the f.CaO contents effect on the cement. Finally, compare to OPC, the fly ash cement that was made had a lower hydration heat and higher fluidity.

High-strength high-durability cement is used these days, and it consists of low heat Portland cement（LHC）and silica fume（SF）. However, LHC-SF system is uneconomical and utilizes a small amount of industrial wastes. In contrast, moderate-heat Portland cement（MPC）utilizes more industrial wastes, and the limestone powder（LSP）is an economical material. Therefore, MPC-LSP system is expected as the new high-durability cement. This paper investigates the fluidity of low water-to-powder ratio MPC-LSP paste with superplasticizer from the point of the packing fraction and the initial hydration. To make the fluidity higher, the authors used the packing simulation, and the LSP mass ratio to MPC was configured to make the highest packing fraction. The fluidity of configured MPC-LSP paste was higher than that of LHC-SF paste. In addition, the increase in the LSP ratio to MPC increased the fluidity of MPC-LSP paste, and this tendency was stronger at low water-to-powder ratio. On the other hand, the cumulative heat liberation of MPC-LSP paste was lower than that of LHC-SF paste. In addition, the increase in the LSP ratio to MPC decreased the cumulative heat liberation of MPC-LSP paste, and this tendency corresponded with the fluidity. It is considered that LSP influenced on the initial hydration of calcium-aluminate phase in cement, resulting in the higher fluidity. The initial hydration is an important factor in the fluidity of cement paste.

The reaction ratio of the fly ash of FA-CH paste was measured. The mixing water was adjusted to pH 12.5, 13.0 and 13.5 using NaOH. The elution of Al ions takes place at early stage of the pozzolanic reaction by alkali stimulation. Al ions work as network modifying oxides when there are present in 5 and 6 coordination. The relationship between the coordination number of Al ions in the glass and the pozzolanic reactivity has been discussed. The content of 5 and 6 coordination of Al ions was calculated from the charge balance of the glass composition. “M_G” was defined as the degree of network modifying oxidation considering the coordination number of Al ions and blaine fineness. There was a high correlation between M_G and the pozzolanic reactivity of the experimental results in this study. As a result of applying M_G to previous studies, the pozzolanic reactivity tended to increase as M_G increased in fly ash - Ca（OH）₂ paste and cement paste mixed with fly ash. Therefore M_G can be used the index to evaluate the pozzolanic reactivity.

Cement manufacturers are replacing traditional raw materials and fuels with by-products and wastes. Alternative raw materials and secondary fuels contain minor elements which can influence burnability, clinker minerals and cement properties. Burnability affects the amount of free lime which also varies mineral composition and cement hydration. In order to optimize the utilization of alternative sources, this paper evaluated the effects of minor elements on clinker mineral and cement hydration under the conditions of uniform free lime effect and determined the limits of MgO, NiO, CuO, ZnO, TiO₂, and P₂O₅.
Minor elements were differentiated into three groups based on similar effects on clinker minerals. Group Ⅰ, MgO and NiO, was distinguished by the presence of periclase and periclase-like crystal. Group Ⅱ, ZnO and CuO, was characterized by negligible changes to the silicate phase along with the formation of excess oxides which act as retarder on cement hydration at high additions. Group Ⅲ, TiO₂ and P₂O₅ was defined by a decrease in C₃S. The authors recommend the following limits for minor elements based on cement hydration and strength：MgO≤.2.00, for negligible effect, NiO≤1.95％ showed negligible effects, CuO≤0.48％ for negligible effects, ZnO≤0.97％ for beneficial strength gain, TiO₂≤0.50％ showed negligible effects, P₂O₅≤0.91％ for negligible effects.

This paper describes the role of Portlandite on the hydration of C₃A -Gypsum -Portlandite system. Their solid phase was measured by XRD Rietveld analysis and ²⁷Al MAS NMR measurement, and liquid phase was measured by ICP-AES and ion chromatograph. As a result of measurement, two things are confirmed as an effect of the addition of Portlandite. The first one is the amount of amorphous C₄AH₁₃ increases at the initial stage of hydration. Second one is the presence phase of amorphous C₄AH₁₃ is attracted to the C₃A particle surface and shrinks. From the above, the C₄AH₁₃ thin film deposited on the C₃A particle surface densifies and delay the C₃A hydration reaction after thin film formation. In addition, prediction of C₃A hydration was performed by using a phase equilibrium model for the amount of hydration product and ion concentration in liquid phase. It is well known that the prediction of C₃A hydration is so difficult by using only phase equilibrium model. At that time, it was assumed that C₄AH₁₃ can be formed heterogenious, and it was easily generated under the influence of supersaturation state of Ca ions in the vicinity of the C₃A particles, so that good agreement between the measured value and the predicted value was obtained.

This study was performed to generate the highly reactive β-C₂S by heating the calcium silicate hydrates（C-S-H）with high CaO/SiO₂ molar ratio（C/S ratio）at low temperature. Therefore, C-S-H samples were synthesized by double-decomposition method under various conditions. Then, the synthesized C-S-H samples were heated at 600℃, and the heated samples were hydrated. The synthesized C-S-H, the heated samples, and the hydrated samples were analyzed phase composition, chemical composition and BET specific surface area. As a result, the calculated C/S ratio of C-S-H with targeted C/S ratio＝2.0 was about 0.9；however, the C/S ratio of the same C-S-H analyzed by XRF was about 1.2. When this C-S-H was heated at 600℃, wollastonite which has a C/S ratio of 1.0, β-C₂S and α-C₂S were generated. It may be suspected that the C-S-H with C/S ratio of 1.0 and the C-S-H with C/S ratio of 2.0 were coexisted in the synthesized C-S-H, and these C-S-H phases were changed to wollastonite and C₂S respectively. Furthermore, BET specific surface area of the heated C-S-H sample was comparable with the literature value of the highly reactive β-C₂S, and the calcium hydroxide was not generated after hydration. Therefore, it was concluded that the C₂S generated in this study was likely the highly reactive C₂S.

Chloride ion causes the rust of ion rebar, and the rust results in the degradation of the concrete. Therefore the immobilization of chloride ions is necessary for the concrete which is used in salt-damage environments, and the AFm phase generation is important for the immobilization. This paper investigated the Afm phase generation in cementitious materials which are made of low heat Portland cement（LHC）, moderate-heat Portland cement（MPC）, an ettringite-type expansive additives（CSA）, and CaO・2Al₂O₃（CA₂）. In the LHC-CSA-CA₂ type material, the required amount of CA₂ for the AFm phase generation was 6mass％. On the other hand, in the MPC-CSA-CA₂ type material, the required amount was 4.5mass％. This difference between the required amounts relates to the amount of reacted SO₃ and the amount of reacted Al₂O₃. When the molar ratio of reacted SO₃ to reacted Al₂O₃ was less than1, which corresponds to monosulfate, the AFm phases were generated. The resistivity to calcium elution of the MPC-CSA-CA₂ type material was enhanced by the carbonation of the material’s surface. This carbonation generated the calcite coat on the material and it is supposed that this coat decreases the influence of chloride ions on the material. In the non-carbonated inner part of the material, AFm phases still remained.

This paper discusses the influence of calcium nitrite and limestone powder on the strength and the hydration reaction of high volume slag cement （HVSC）. By adding of calcium nitrite, the compressive strength of HVSC mortars are increased. The reaction of BFS similar to OPC is accelerated by calcium nitrite in HVSC. The acceleration of slag reaction by calcium nitrite is related to the formation of AFm（NO₂）. Therefore, though the reaction amount of BFS is increased, AFt is mainly formed by adding of calcium nitrite. The formation of AFt is important for the reduction of shrinkage of HVSC. By adding of both calcium nitrite and LSP, the strength of mortar is similar to that of mortar with calcium nitrite, but the total pore of hardened samples is decreased. This is a very important factor for the improvement of durability of HVSC.

The cement containing a large amount of blast furnace slag（BFS）is the promising material to reduce the CO₂ emission in cement industry. This paper describes the influence of Ca（NO₂）₂ on the hydrates, the hydrated layer of slag grains, and the composition of C-S-H in high-volume-slag cement. The composition of high-volume-slag cement in this paper was the following ratio, OPC（ordinary Portland cement）：BFS：Anhydrite＝30：65：5mass％. The chemical composition of C-S-H was measured by SEM-EDS method. By the addition of Ca（NO₂）₂, the reaction ratio of slag in the high-volume-slag cement was increased, and AFm（NO₂）was generated. In the hydrated high-volume-slag cement paste, a large amount of unreacted slag grains remained. The hydrated layers were observed in the surrounding of the unreacted slag grains. Inner and outer hydrated layers were observed in the hydrated layers. Thicknesses of the layers were approximately 0.5μm and independent of the grain size. The Ca/Si ratio of C-S-H in the high-volume-slag cement paste was 1.34, and the Al/Si ratio was 0.16. The addition of Ca（NO₂）₂ increased the Ca/Si ratio from 1.34 to approximately 1.5. This is because the hydration of cement, especially belite, is accelerated by the adding of Ca（NO₂）₂.

This study investigates the effects of types of superplasticizer and chemical compositions of blast furnace slag on hydration reaction of blended cement containing high volume of blast furnace slag. The hydration reaction of the high-volume blast furnace slag cements were strongly retarded when the superplasticizers containing lignosulfonates or gluconates were added. On the other hand, the addition of poly-carboxylate based superplasticizer had less effect on the retardation of hydration reaction. It was assumed that superplasticizer decreases the solubility of cement and disturbs the reaction of slag. And the retardation of hydration increased with increasing an amount of superplasticizers.
With the increase of Al₂O₃ contents in blast furnace slag, the time of secondary peak shown in heat flow curve became faster for the blended cements containing 90wt％ of slag, whereas the time of secondary peak for the blended cements with 70wt％ of slag was almost same. And this trend occurred clearly when it using superplasticizer, compare with no use. The reason for the difference in hydration reaction was estimated that amount of hydrates are different formed at early age for the blended cement containing higher volume of slag and the trend of hydration reaction at later stage is change from early age.

This paper describes the effect on physical properties in earlier age of concrete made with Portland blast furnace slag cement CLASS C by expansive additives. Setting time, compressive strength and length change have been measured. By adding expansive additives to concrete of Portland blast furnace slag cement CLASS C, setting time was found delayed, compressive strength has been improved in earlier age instead. In the regard of length change measurement, since initiating of water-immerse curing was not able to comply with conventional standard of JIS A 6206, due to quite slower strength development, this standard did not work well enough. The alternative strain measuring in accordance with JCI-009-2012 was found appropriate to investigate the expansive performance of materials having low strength development character.

Grossite which consisted of uniformed CaO・2Al₂O₃ is to be manufactured by rotary kiln under over 1600℃ temperature. Addition of slight amount of Fe₂O₃ raw material makes the melting point of Grossite lower（＜1400℃）. While the function of Fe₂O₃ for manufacturing conditions has not been investigated well. In this paper, we researched the sintering process of Grossite by utilizing dynamic microscopic observations, SEM-EDS and XRD. According to dynamic microscopic observations of CaO・1.8Al₂O₃ 0.2Fe₂O₃ at a temperature of 25℃ to 1500℃ result Fe₂O₃ acted as liquid over 1300℃ and existed as a small particle（20μm）with metallic luster. SEM-EDS analysis of CaO・1.6Al₂O₃ 0.4Fe₂O₃ burned at 1200℃ and cooled by air revealed the ratios of Fe/Al to Ca were not constant. By XRD and Rietveld analysis of CaO・2Al₂O₃ and CaO・1.8Al₂O₃ 0.2Fe₂O₃ at a temperature of 25℃ to 1500℃, Fe₂O₃ was converted to calcium ferrites such as CaO・2Fe₂O₃, CaO・Fe₂O₃, 2CaO・Fe₂O₃ at 1000 to 1100℃. Yield of Grossite from CaO・1.8Al₂O₃ 0.2Fe₂O₃ at 1500℃ was higher than CaO・2Al₂O₃. In addition, a part of Al which is constitution of Grossite crystal structure was substituted to Fe. It was also supposed that calcium ferrites existed as melting liquids form and promoted the diffusion of Al₂O₃.

Studies on physical adsorption to SiOH sites on the surface of C-（A）-S-H, which is considered to be dominant phase in blended-cement system, have been conducted in order to predict the amount of bound chloride ion in the hydrated cement. However, authors best knowledge, there is no proper model that can reproduce the physical adsorption of chloride on C-（A）-S-H with different Ca/（Si＋Al）ratio. The studies on the structure and the change of the SiOH site due to the change in the Ca/（Si＋Al）ratio are still insufficient because of many unknown parts of the structure estimation based on the bonding state of the atoms. On the contrary, C-S-H structure is changed by Ca/Si ratio, pH, curing temperature, and others. For example, for a high Ca/Si ratio, Si atom of the bridging position becomes less and SiOH site decrease. However, in the case of C-A-S-H, some Si atom is exchanged to Al atom and thus SiOH site changes to AlOH site. The effect of Ca/（Si＋Al）ratio on C-A-S-H structure and SiOH（AlOH）site is still not clear and the structure estimation considering the bonding state of atoms is difficult. Therefore, in this study, we synthesized C-A-S-H with different Ca/（Si＋Al）ratio and studied the detailed structure of C-A-S-H by using ²⁹Si MAS-NMR and ²⁷Al MAS-NMR. Two unknown peaks in the ²⁷Al MAS-NMR spectrum were found, and ²⁹Si MAS-NMR spectrum analysis and structure study were conducted based on this.

This study was performed to evaluate the effects of C/S ratio and aluminum substitution ratio on hydrogen sulfide adsorption ability of the calcium-silicate-hydrates（C-S-H）and the calcium-aluminum-silicate-hydrates（C-A-S-H）and to clarify the hydrogen sulfide adsorption mechanism of C-S-H and C-A-S-H. As a result, the hydrogen sulfide adsorption ability was increased with decreasing the C/S ratio of C-S-H, and the ability was increased by using the aluminum substituted C-S-H with low C/S ratio. Moreover, the amount of water vapor adsorption and the BET specific surface area of C-S-H were increased with decreasing the C/S ratio. On the other hand, the amount of water vapor adsorption of the C-A-S-H was increased in a meso pore region（about 2-50nm）as compared to the C-S-H with same C/S ratio；however, the H₂O-BET specific surface area of the C-A-S-H was little differentiated from the C-S-H with same C/S ratio. Therefore, it was suspected that the hydrogen sulfide adsorption ability was increased because of the increasing of the H₂O-BET specific surface area of C-S-H caused by decreasing of C/S ratio, and because of the increasing of AlOCa^＋ adsorption sites of C-A-S-H caused by aluminum substitution for silicate.

Sulfate attack is known as one of the deterioration phenomena of concrete structures. In particular, delayed ettringite formation is considered a serious problem. According to previous researches, it has been pointed out that delayed ettringite formation is affected by the hydrates coexisting around monosulfate, however it has not been shown experimentally yet. The purpose of this research is to discuss that the effect of pretreatment drying of monosulfate and coexisting substances on ettringite formation. As a result, when a mixture of monosulfate and C-S-H was mixed and hydrated using an aqueous solution of Na₂SO₄, the amount of ettringite was increased. In particular, it was shown experimentally that the amount ettringite was greatly increased when coexisting the C-S-H with high C/S ratio. In addition, it has been shown for the first time that amount of the ettringite is further increased after hydration with an aqueous solution of Na₂SO₄ as a result of strongly pre-treatment drying of monosulfate and coexisting C-S-H. Therefore, it maybe suggested that the expansion due to sulfate attack was affected by coexisting of strongly dried C-S-H with high C/S ratio.

In order to clarify the mechanism that monosulfate transforms into ettringite, this study experimentally observed the transformation from monosulfate into ettringite when pure monosulfate phase immersed in the solution containing sulfate ions. The results of this study showed that there was an induction period that the reaction was controlled by dissolution of monosulfate in the early stage when sulfate ion attacked to monosulfate. In addition, after this period, there was an acceleration period that the precipitation rate of ettringite increased with time. Moreover, it was found that the monosulfate kept dissolving even in the acceleration period, and nucleation of ettringite was likely to continue.

A quantitative analysis of hydration heat for ordinary portland cement using the thermochemical calculations are studied to develop the analysis method evaluating the hydration heat of cement from its mineral composition measured without a preparation of actual cement paste. This analysis traces the measurement process of hydration heat regulated by JIS R 5203, i.e. formulation of the dissolution reaction for the unhydrated and hydrated cement into the acid solution and determination of the dissolution heat of the dissolution reaction with enthalpy values provided by the existing literatures. In order to improve the estimation accuracy of hydration heat by the thermochemical calculations, the enthalpy values of the dominant cement minerals（C₃S, C₂S, C₃A, C₄AF）and the C-S-H are adjusted to match the calculated solution heat of the unhydrated and hydrated cement with the measured solution heat. This analysis is thought to have an adequate estimation accuracy after comparing the thermochemical-calculated 28d hydration heat determined using the measured mineral composition of cement provided by the actual plant with the measured hydration heat.

In this study, the tortuosity of the compression molded specimen made from carbonated synthetic C-S-H was measured from oxygen diffusion coefficients to understand the effect of carbonation on the mass transfer of hardened cementitious paste. From the experimental result, mass transfer resistance decreased due to carbonation. The specific surface area of C-S-H decreased with the progress of carbonation. From the above result, decrease in the surface area of C-S-H due to carbonation brings about the decrease in the mass transfer resistance. From the specific surface area of the carbonated synthetic C-S-H, it was suggested that the reaction of C-S-H decomposing into CaCO₃ and SiO₂ was dominant.

In this study, compression molded C-S-H specimens were prepared to study the influence of C-S-H mass transfer properties in hardened cementitious materials. C-S-H with various CaO/SiO₂ molar ratio were synthesized. The compression molded specimens were prepared using a powder molding machine and a cold isostatic press machine. The condition of the compression molded was decided. Moreover, by evaluating the tortuosity in oxygen diffusion by conducting oxygen diffusion test and measurement of pore size distribution of the compressed C-S-H. The tortuosity is correlated with the surface area of C-S-H.

In this research, chloride ion penetration into a mortar in a simulated tidal zone was experimentally examined. As a result, in the case of the dry-wet cycle at every 6 hours, the chloride ions penetrate into a mortar associated with the transportation of liquid water（advection）when the degree of saturation in the inner part of specimen（deeper than around 6cm）was low. Moreover, the mechanism of chloride ion penetration is advection in the cases of W/C＝0.4 and 0.5 mortar of low initial degree of saturation under continuous saline absorption. On the other hand, chloride ion penetration was promoted or suppressed in comparison with advection in the cases of W/C＝0.5 with high initial degree of saturation, and W/C＝0.6.

Supplementary cementitious materials（SCMs）especially fly ash（FA）can play significant role in reducing CO₂ emission produced by the cement industry and improving waste management by recycling the industrial waste exhausted from coal fired power plants. However, FA cement has the lower initial strength than that of ordinary Portland cement（OPC）. In order to improve this problem, high C₃S cement（HAC）and limestone powder（LSP）was used instead of OPC in FA cement in this study. HAC, FA and LSP blended cement（HAC-FA-LSP）was reported that it had the same compressive strength as OPC at 3 to 56 days of age. However the hydration reaction of HAC-FA-LSP is not investigated enough. In this paper, the hydration product and pore size distribution of HAC-FA-LSP is revealed. The study findings indicate that the amount of monosulfate is decreased. Hemicarbonate and monocarbonate is formed in HAC-FA-LSP. And according to MIP measurement, the porosity of HAC-FA-LSP at 7days aged is decreased compared with OPC-FA. However, HAC-FA-LSP at 28day and 91days aged have no significant change on pore distribution compared with OPC-FA.

An artificial barrier with cementitious material in a radioactive waste disposal facility will be affected for a long term by high temperature loading due to radioactive heat emission. In this study, some basic experiments were conducted to evaluate the long-term thermal loading effects on hardened mortar properties using sole OPC and OPC partially including fly ash（as called FAC）. In the result, FAC revealed that whereas the continuous pore volume much decreased shortly after high temperature exposure, it increased with time passing under the same condition. The similar tendency was observed under sealing condition at high temperature as well. These findings suggest the possibility that C-S-H structures have changed due to not only drying bound water but also successive thermal loading itself.

Recently, the demand for precast concrete have been increased with the object for construction, productivity, quality control and the shortening of a construction period. In addition, the study for compressive strength of fly ash concrete under the steam curing has been investigated. However, the effect of various condition such as, temperature history and curing condition（water curing or air curing）after steam curing on concrete performance has not been clarified. Regarding the Fly ash concrete cured in temperature history, the study of compressive strength under long term curing age has not been enough.
From the background, the relation between the phase composition and compressive strength of Fly ash was investigated in this study. In this study, high early strength cement replacement with Fly ash（named FAHC）was focused. To clear the effect of the replacement of Fly ash for compressive strength under the period early age between long term ages, the phase composition of hardened Fly ash cement paste was measured. Furthermore, in order to evaluate the effect of the various binder types, the compressive strength in FAHC paste was evaluated by Gel/Space ratio using phase compositions. It is clarified that the compressive strength in FAHC paste is a value at the same level as Ordinary Portland cement replacement with Fly ash at early age. Furthermore, Oxygen and chloride ion diffusion coefficient decrease by replacement with Fly ash in FAHC.

The importance of maintenance and repair of existing concrete buildings has increased. Therefore, it is necessary to know the exact deterioration condition of a concrete building structure, so it is required to accurately measure the pore structure. As one of the measurement techniques, thermoporometry has been proposed. Thermoporometry does not need drying and applying high pressure to specimen during measurement, so there is little risk of damage to the cement paste. In this study, we measured some physical property（uniaxial compressive strength, ultrasonic velocity, electric conductivity, and chloride ion diffusion）and pore structure of OPC paste and fly ash cement paste. And we investigated the relationship between the physical properties and the pore structure measured by using thermoporometry and mercury intrusion porosimetry. As a result, the uniaxial compressive strength and the ultrasonic velocity can be estimated by using pore volume measured by thermoporometry and mercury intrusion porosimetry. Transport properties such as the electric conductivity and chloride ion diffusion could be estimated by separating each OPC paste and fly ash cement paste. And it was suggested that the diffusivity could be estimated by using the quantity of pore volume detected in the freezing process around －15℃ which is the connected capillary pore volume.

The influence of slowly cooled furnace slag exerts on strength development of hardened mortars containing blast furnace slag, and those mechanisms were investigated. Hardened mortars are consisted of blast furnace slag as major binder and of slowly cooled furnace slag sand found fine aggregate. The flow value difference was small between types of fine aggregate, while early to long age compressive strength of hardened mortars containing slowly cooled furnace slag sand were higher than that containing natural sand. It is assumed that the hydroxide ion dissolved from slowly cooled furnace slag sand which was carried by calcium ion has accelerated of blast furnace slag.

In Japan, salt attack damages reinforced concrete structures particulary from ocean supplied water and from snow melting agent which one of the major deteriorating factor of concrete structures. Therefore it is necessary to improve the resistance of chloride ion diffusion of concrete to achieve sustainable society. This paper investigates the chloride ion diffusion behavior in blast furnace slag cement with CaO・2Al₂O₃. Since the use of CaO・2Al₂O₃, the penetration depth of chloride ion in the mortar was found to reduce, the mechanism had been evaluated through the hydration analysis. The amount of hydrocalumite was increased as a function of CaO・2Al₂O₃ dosage. This indicates that the amount of immobilizible chloride ion as Friedel’s salt is increased according with CaO・2Al₂O₃ dosage. In addition to that, the reduction of both total pore volume and capillary pore volume after salt water immersion became remarkable by adding more CaO・2Al₂O₃. By this change, blast furnace slag cement with CaO・2Al₂O₃ becomes more dense hardened mortar than that without CaO・2Al₂O₃ after salt water immersion. From these results, it was confirmed that the resistance of chloride ion diffusion in blast furnace slag cement is improved by the use of CaO・2Al₂O₃ in the view point of both chemically and physically, that is by immobilization of chloride ion as Friedel’s salt and densification of pore structure.

The aggregate composed primarily of CaO, Al₂O₃（CaO・Al₂O₃ aggregate）generates hydroculmite by hydrating with calcium hydroxide which is a cement hydrate, and reacting and generate Friedel salt when a chloride ion acts. When the calcium aluminate is used for concrete as aggregate, a hydration was occurred at the aggregate surface. As a result, the possibility that a transition zone of concrete was modified by using the CaO・Al₂O₃ aggregate was suggested. In this research, physical properties and substance penetration property of the concrete which using with calcium aluminate aggregate were examined. Regarding the strength development property, it was confirmed that the concrete using with CaO・Al₂O₃ aggregate showed higher compressive strength compare with the concrete using with natural aggregate but there was not confirmed interrelation between compressive strength and absorption property of concrete. This was considered to be caused by generation of Hydroculmite and Friedel’s salt which were generated by the reaction of CaO・Al₂O₃ aggregate. By the result of SEM-EDS, an aggregate interface became the dense with the concrete using the CaO・Al₂O₃ aggregate in comparison with concrete using the natural aggregate, and it was confirmed that a different hydrate was generated inside and outside the outer layer of the CaO・Al₂O₃ aggregate.

Clinker with increased amounts of C₃A and SO₃（C₃A：10-14％, SO₃：1.1-2.5％）was prepared by an electric furnace, and Cement was prepared with adding a certain amount of reagent gypsum（Gypsum SO₃＝1.2％）and grinded until 3,300cm²/g fineness by bond mill. The physical properties and durability of the sample cement was investigated. As a result, as C₃A and SO₃ in clinker increased, the setting time tended to be accelerated and the compressive strength hardened at 3 days of age, but it dropped as the age of long term. Also, as C₃A in clinker increased, the dry shrinkage strain of mortar increased, and as SO₃ in clinker increased, the dry shrinkage strain of mortar decreased. As C₃A of clinker increased, the cumlative heat of hydration of cement increased. On the other hand, as SO₃ increased, cumlative heat of hydration increased at several days after adding water but declined after several days. As both increase, the hydration exothermic curve changes, and the hydrate formation rate varies depending on both components.

The air mass transport in concrete is influenced by moisture condition. Since the moisture condition of concrete change with drying condition, such as solar radiation, weather, and rain, it is important to clarify the relation between air mass transport and the moisture condition of concrete for concrete durability. On the other hand, it is obvious that the pore structure of hardened cement paste change with drying condition. And, the properties of hydration products also change with drying condition. However, the relation between air mass transport and pore structure, hydration products of hardened cement paste exposing various drying condition have not been clarified.
The purpose of this study is to estimate the relationship between air mass transport and pore structure, hydration products of hardened cement paste drying various relative humidity. The hardened cement paste, using blast furnace slag, was dried at RH 80％, 56％, 43％ and 22％. Experimental results show that the relation between Oxygen diffusion coefficient of hardened cement paste and open porosity is independent of materials and mix condition. On the other hand, oxygen diffusion coefficient using blast furnace slag is smaller than that using ordinary Portland cement in the case of high porosity. It is investigated in this point in detail. As the drying humidity decrease, the pore size distribution was coarsened. Particularly, porosity more than 10nm was increased. In addition, the specific surface area of hydration products was decreased. Furthermore, it is suggested that the influence by the change of macro pore structure dominant to air mass transport at high relative humidity, and the change effect of properties of hydration products dominant at low relative humidity.

In order to evaluate the expansive properties of expansive concrete, uni-axial restraint test method is stipulated in JIS A 6202 and it have been used widely as the only expansive test method. But, actually, bi-axial or tri-axial restraint condition is usual in structures and multi-axial restrained test method such as using concentric double pipe have been tested and developed. Many studies have been conducted on the effects of various experimental conditions, but, in particular, researches about the effects of eccentricity of inner steel pipe against outer steel pipe are still very limited.
This paper aims at investigating expansive properties of expansive concrete under restrained by eccentric double steel pipe with different thickness of both steel pipe and CTOC（center to center）distance of double steel pipe.
The following results were obtained,
1）By expansive force of expansive concrete, circumferential tensile strains are observed on an outer steel pipe and compressive strains are occurred on an inner steel pipe.
2）Considering the effect of CTOC distance between the outer and inner steel pipe, expansive forces of concrete mainly act on the outer steel pipe at the point of maximum or minimum CTOC distance, on the other hand, at midpoint of CTOC distance, expansive forces of concrete mainly act on the inner steel pipe, in case of using a thin-walled outer steel pipe.

Recently, in the concrete field, in order to reduce the environmental impacts, the application of industrial wastes and byproducts is promoted. However, concrete containing industrial wastes and byproducts may be hazardous to human and the environment due to possible leaching of heavy metals. On the other hand, it is known that leaching of heavy metals is dependent on environmental conditions. In this study, we investigated experimentally to understand the adsorption / desorption characteristics of lead in cement hydrates and the internal changes when cement hydrates contact with different kinds of solutions and solutions at different values of pH. As a result, when cement hydrates contact with different types of chloride solutions, a high amount of Pb adsorption can be seen in MgCl₂ solution but a significantly low amount in CaCl₂ solution. Besides, it is also found that a lower value of pH in solution results in a higher amount of Pb adsorption.

Strength is produced by the hydration reactions of cement, so much research has been carried out into the effect of hydration reactions on strength properties. However, some cases have been confirmed where gel space ratio, the theory that connects hydration reactions and strength properties, does not apply when admixtures are used. In this research, the objective was to construct a method of estimating the strength from hydration reactions, that is not dependent on admixture percentage and type. The parameters were binder composition, water to binder ratio, and curing temperature. The effect of hydration reactions on the strength properties of blended cements in which a prescribed percentage of ordinary Portland cement was replaced with various admixtures was investigated. Hydration reactions were analyzed using the cumulative heat of hydration obtained using a conduction calorimeter. The cumulative heat of hydration was allocated into that originating from the Portland cement and that originating from the admixtures and the relationships between the cumulative heat of hydration and the strength properties were compared and analyzed. The results showed that the relationship between heat of reaction originating from the admixtures and the strength properties was different from that for ordinary Portland cement, and this difference was defined quantitatively as a material coefficient. Also, gel space ratio has been extended so that by using the material constants it enables the strength properties to be estimated from the cumulative heat of hydration for different binder composition, water to binder ratio, and curing temperature.

In order to ensure long-term safety operation of nuclear power plants, it is necessary to evaluate the soundness of concrete used in the plants against various deterioration events. Irradiation environment is a particularly characteristic boundary condition of the materials for nuclear power plant, and consequently, it is important to grasp its deterioration mechanism.
The effect of gamma-ray irradiation on carbonation of cement paste using high early strength Portland cement was investigated. XRD/Rietveld analysis, TG-DTA, FT-IR, water vapor sorption and nitrogen sorption measurements were conducted on the samples with/without ⁶⁰Co gamma-ray irradiation up to the dose about 50,000 kGy. As a result, the differences in carbonation under gamma-ray irradiation environment and non-irradiated environment were identified from the viewpoint of phase compositions and microstructure, as shown below.
From the experimental results, it was confirmed that large portion of C-S-H was carbonated and vaterite was mainly precipitated under gamma-ray irradiation, whereas calcite was mainly precipitated through the carbonation without irradiation.
In addition, from the viewpoint of microstructure, it was confirmed that the hardened cement paste carbonated under gamma-ray irradiation had less amount of cavitation in nitrogen sorption isotherm measurement at 77K than that carbonated without gamma-ray irradiation, and a sharp change of desorption amount around 40％ RH in water vapor sorption isotherm measurement by volume method at 293 K, which was originally confirmed in the hardened cement paste before irradiation. All these experimental facts suggest that the similar microstructure originated by non-carbonated C-S-H in hardened cement paste before irradiation was preserved under gamma-ray irradiation condition with forming vaterite through carbonation of C-S-H.

In this study, using electromagnetic pulse method, effective input condition for evaluating initial defects of post-installed adhesive anchor bolt which are difficult to be detected by visual inspection is discussed. First, using acryl specimen of which material is homogeneous, turns of exciting coil, applied voltage and electric capacity of pulse current generator were changed for clarifying how the magnetic properties such as magnitude and rise up of magnetic flux density affect the vibration properties of the bolts which simulate defects. Next, using concrete specimen as composite material, effective measurement position and optimum input condition were found for detecting incomplete filling of adhesive in the anchor hole due to vacant portion which are difficult to find by visible inspection. Finally, focusing on the wave energy and frequency response of received signal, it was found that there’s a possibility of detecting the defects effectively using the input conditions that the magnitude of magnetic flux density is large at the head of bolt, and the rise up velocity of magnetic flux density is large.

A semi-flexible pavement is a pavement designed to prevent plastic deformation due to loading. In order to achieve this performance, it is necessary to be adequately filled with cement grout into gap in porous asphalt pavement. However, the evaluation method for the filling ability of cement grout has not been established yet. In order to evaluate the filling ability, a funnel test is usually used. And in Japan, a P-funnel test is used for it. However, this test method is not for evaluating the filling ability but the viscosity of cement grout.
In this study, by using several types of cement grout with different viscosity, the relationship between filling ability and results of several kind of testing method was investigated. Based on the results, it was found that table-flow test was more suitable for evaluating method than a funnel test.

In this study, the evaluation method of viscosity of mortar and concrete under gravity and vibration was investigated. Based on Rankin’s earth-pressure theory and Bingham model, the estimation method for yield stress and plastic viscosity of mortar was proposed using slump flow test result. As a result, except for short deformation time case, it is thought that the proposed method can estimate the viscosity of mortar under gravity. And also, the estimation method for viscosity of mortar and concrete under vibration based on the deformation of mortar and concrete was proposed by using the driving force and the resistance of deformation. In the case of same water-cement ratio and surface area of total aggregate per unit weight of cement paste, it was found that the estimated viscosity of concrete under vibration was almost same as that of mortar.

Although it is apparent that the deterioration due to alkali silica reaction is caused by the expansion produced by alkali-silica gel generated by the reaction between alkali and some reactive silicious minerals in alkali-reactive aggregate, there is still controversial for the mechanism of alkali-silica gel staying in the reactive aggregate and producing the expansion pressure and cracks in the concrete. Therefore, this paper tried to identify the mechanism of expansion pressure through some simplified element test using highly reactive andesite, which focuses on alkali-silica gel leaching / staying in the reactive aggregate. A series of experiments, the fluorescent observation of the alkali-silica gel distribution appeared on the cut surface of the reactive aggregate, which immersed into some kind of alkali solutions, hardened gypsum pastes or hardened cement pastes and the crack distribution in the cut surface of the cement paste matrix was carried out. As a result, the alkali-silica gel leached out and did not stay in the reactive aggregate without dense hardened cement paste matrix around. Furthermore, the alkali-silica gel in the dense hardened cement paste seems leach gradually from the reactive aggregate into hardened cement paste matrix without any visible cracking and this trend should be accelerated in case of high temperature or high water to binder ratio.

This study proposes a flexural strength management system with cumulative maturity concept and verifies for construction crack of “early opening to traffic” concrete pavement（One Day Pave, ODP）. ODP employs special mixture proportions with general purpose materials to accelerate strength development and shorten hardening period down to literally one day or less. On the other hand, the time for flexural strength management becomes shorter. Therefore the strength should be precisely and effectively evaluated during the curing period. This study developed a strength evaluation method using cumulative maturity, which is easily estimated by measured concrete temperatures. Also the verification result of construction crack shows that insulated curing is important not only for strength development but also for prevention of construction crack.

It is known that the drying shrinkage strain of concrete is affected by the material, mix proportion of concrete, environmental conditions such as ambient temperature and humidity. And the temperature history at curing also affects. This paper shows the effect of temperature history during curing on drying shrinkage strain and pore size distribution of concrete. Dry shrinkage strain, moisture loss amount and pore size distribution of concrete cured under various temperature histories were measured. As a result, the longer curing at higher temperature, the drying shrinkage strain of concrete decreases, but the moisture loss of concrete increases. As concrete cured at high temperature, the volume of fine pores with diameter of 6nm or less decrease, and the pore volume with diameter of 50nm to 100nm increases. So, concrete cured at high temperature becomes coarse pore structure. There is a correlation between pore volume diameters of 6nm or less and dry shrinkage strain. On the other hand, there is a negative correlation between the pore volume of 50nm to 100nm in diameter and drying shrinkage strain. For those reason, although moisture loss of concrete cured at high temperature becomes increases, drying shrinkage strain becomes small. Therefore, the progress of carbonation of concrete cured at high temperature becomes faster.

Electrochemical non-destructive inspection of steel corrosion needs to use electric equivalent circuit model. Electric characteristics of hardened cementitious materials change according to mix proportion and chloride content. However, the relationship between the electric equivalent model and chloride content has not been clarified. Therefore, this study was performed to find out the effects of chloride content on the electric equivalent circuit model of the hardened cementitious materials. Previous studies have reported that the pore structure and the ion composition of the pore solution change due to chloride content. The hardened cementitious materials permeated chloride ions were used in this study. The effects of the pore structure and the ion composition of the pore solution on the electric equivalent circuit model of hardened cementitious materials were examined.
It is found that chloride ions affect the surface potential of pores. The charge transfer resistance of the cementitious materials permeated chloride ions can be evaluated by the pore structure, the ion compositions of the pore solution and chloride contents.

Cement industry is one of the energy-intensive industries. Though Japanese cement industry has achieved top-class energy efficiency in the world, the development of the further energy saving technology is needed from the view point of global environmental protection such as the reduction of carbon dioxide and fossil fuel consumption. In the past study, we reported the possibility that the burning temperature of clinker could be lowered 100 degrees by adjusting major mineral composition, namely increasing C₄AF and decreasing C₂S instead. And properties of the cement used low burning-temperature type clinker and the concrete used the cement were at the same level as Ordinary Portland Cement. In this study, we manufactured Blast Furnace Slag Cement Type B（BB）using low burning-temperature type clinker by actual finish mill, and evaluated properties of cement, mortar and concrete. As a result, we confirmed that cement and mortar properties of setting, strength development and chemical durability of BB using low burning-temperature type clinker were at the same level as BB using Ordinary Portland Cement clinker. And, although drying shrinkage of BB using low burning-temperature type clinker was slightly bigger than BB using Ordinary Portland Cement clinker, other properties of concrete were at the same level as BB using Ordinary Portland Cement clinker.

Recently, global warming is a serious problem. In Japan, therefore, reduction of CO₂ emission is an important problem in any industry. Especially, in construction works of which the scale is very large, an action for CO₂ emission reduction is demanded, and it is necessary to deal with reduction of CO₂ emission. This paper describes the evaluation of concrete property and test-construction of 1DAY PAVE reduced CO₂ emission and calculated CO₂ emission and compare with 1DAY PAVE reduced CO₂ emission with 1DAY PAVE using HC alone. Due to obtain bending strength 3.50N/mm² which is able to traffic 1day later of construction, 1DAY PAVE was used high strength portland cement and has a lot of unit content of cement than general pavement concrete So, we mixed blast furnace slag cement type B（BB）in 1DAY PAVE, and evaluated concrete property and test-construction was performed. As a result, the bending strength of 1DAY PAVE mixed BB was more than 3.50N/mm². And 1DAY PAVE mixed BB could be constructed like 1DAY PAVE using HC alone. As for CO₂ emission, the emission for 1DAY PAVE reduced CO₂ was less than 1DAY PAVE using HC alone, in the case of 50％ replacing a part of BB with HC the emission was less 20％ than 1DAY PAVE using HC alone.

Quality of concrete in structure is believed to be affected by construction conditions including seasons of placement and curing conditions. Because the stripping time of sheathing board particularly affects the drying of early-age concrete, numerous studies have been reported, while those deal with concrete in structures of actual constructions are very scarce. Hence the influences of sheathing board removal on the strength development of various types of concrete were studied using imitated wall elements. Parameters included season of placement, type of cement and water-binder ratio. Specimens for compressive strength measurement were cored from the imitated wall elements at ages up to 364 days. As a result, it was confirmed that, when sheathing boards were removed at low concrete strength development stages, the compressive strength of concretes in structure up to the age of 91 days became lower than that of the on-site standard curing specimens due to influences of drying. However, the difference in compressive strength by the unmolding time tended to become smaller at ages greater than 91 days. It is concluded that the time of sheathing board removal may not pose marked influences on the long them concrete compressive strength in structure. This tendency was particularly notable for concrete with a low-heat type cement that is expected to have strength development at ages after 91 days.

The suppressing effect of blast furnace slag（BFS）on the ASR expansion of seawater-mixed concrete was investigated. Replacement level of BFS above 40wt％ was turned out to prevent ASR expansion through the concrete prism tests for 3 years. Some analytical results suggested that the formation of C-S-H with lower Ca/Si ratio contributed to reduction in alkalinity of pore solution. From these results and thermodynamic modeling, the method to decide replacement level of BFS to prevent ASR expansion was discussed.

The use of supplementary cementitious materials, such as slag or fly ash blended cement, in concrete have been increasing recently considering the environmental impact of Portland cement and use of industrial by-product as well as for better strength and performance. However, it has been reported that slag blended cementitious materials have low resistance in freezing and thawing environment. In this paper, the influence of blast furnace slag addition on the expansion and shrinkage of blended cement paste during freezing and thawing processes was studied. The expansion and shrinkage experimental results show that the slag addition causes an increasing expansion at around －40℃. Furthermore, the curing period influences the expansion and shrinkage behavior of blended cement. The behavior was analyzed using the model proposed by authors. By comparing the simulation and experimental results, the model could reproduce the expansion and shrinkage behavior of slag blended cement past cured at 70 days. However, the simulation results are not agreed well with experimental data for the specimens cured at 14 days. The microstructure of early age sample might be broken during the processes of freezing and thawing and causes the differences. Furthermore, expansion behavior at around －40℃ affect the volume changes due to hydraulic pressure.

Focusing on shrinkage reduction effect and scaling resistance of RC road bridge deck specimens using fly ash, expansive materials and small sized balloon component, the performance was compared to that with commonly used concrete. Experiments revealed that fly ash concrete using both expansive material and small sized balloon component had compressive strength equivalent to that of commonly used concrete. Air content was 6.0％ or more. Further, it had higher scaling resistance as compared to commonly used concrete and also excellent shrinkage reducing performance. Finally, it was estimated that these improvements in performance were caused by the effect of expansive material and small sized balloon component.

In this study, the influence of R₂O and SO₃ content independently added on DEF expansion was investigated assuming mortar portion of concrete with unit cement content of 300kg/m³. Two types of cement（HPC and OPC）was used and the mortars were affected by high temperature at 70, 80 and 90℃. The result of the limit values obtained in this study almost agrees with the content indicated by Guidelines for Control of Cracking of Mass Concrete（2016）JCI, and it supports the proposal of the limit values of concrete temperature to prevent the DEF cracking. However, in the range where the limit value is 65℃, when the R₂O content is high, it is necessary to lower SO₃ content from 17kg/m³ to 15kg/m³. In OPC mortars, the composition range of R₂O and SO₃ where expansion occurs is smaller than HPC. As the R₂O and SO₃ content increase, the expansion of DEF tends to increase. When the SO₃ content is large, it expands regardless of the R₂O content. When the salt type of R₂O and SO₃ is changed, there is a small difference in the final expansion, the influence of the difference in chemical species on the DEF expansion is also small.

Nowadays, there is necessity to consider the degradation phenomena of concrete with sulfate derived from groundwater and underground soil in relation to long-term durability of concrete structure, and material design for the sulfate resistance is required. Also, as sulfate deterioration changes hydrate and pore structure generated by reaction between sulfate ion and cement hydrate every moment, it is indispensable to consider mass transfer behavior in evaluating long-term durability. On the other hand, there is a need for effective use of industrial by-products. Therefore, the purpose of this research is to evaluate the effect of hardened cementitious materials using CaO-MgO-SiO₂-based materials from industrial by-products with autoclave curing to the sulfate resistance, and to clarify the mechanism of sulfate resistance from the view point of the changes in hydration products and pore structure including secondary products after sulfate entry on the material transfer property. As a result, the generation of tobermorite and calcium magnesium silicate hydrate having Si-O bonds equivalent of and tobermorite could possibly contribute to the sulfate resistance. Furthermore, unreacted akermanite and C-S-H remaining in the cured body reacted with the sulfate, and the formation of secondary hydrate such as silica gel with high degree of polymerization resulted in complicated pore structure and suppression of material transfer properties.'

The properties of concrete surface which influence the durability of concrete structure will be affected greatly on curing conditions. Therefore, the general environment, in case of using the normal portland cement, the wet curing has to carry out for 5 days. The occasion using the poretland-blast furnace slag cement typeB, the wet curing has to carry out for 7 days. However, the influence of durability that drying concrete surface before preparation of wet curing isn’t obvious. In this study, the effects of demolding timing and the wet curing timing on air permeability, surface hardness and strength of concrete with normal portland cement and poretland-blast furnace slag cement typeB were investigated. As a result, the following two became clear.
（1）If the demolding timing became early, the quality of concrete surface became badly. The one of the concrete with poretland-blast furnace slag cement typeB was more influential than the concrete with normal portland cement. However, the wet curing was performed even if mold was removed early, the surface quality of concrete could be improved.
（2）The coefficient of air permeability and the rebound number didn’t undergo by the influence of drying concrete surface before preparation of the wet curing. However, the compressive strength of cover concrete was small, when the wet curing starting became late after demolding. And the influence of lower concrete strength, the concrete with poretland-blast furnace slag cement typeB was larger than the concrete with normal portland cement.