The concentration of chloride and sulfate ion in the mixing water (pore solution) including chloride ion of 1.0wt.% to cement and the amount of hydrates in cement suspension at high w/c were measured for investigation of behavior of chloride ion in fresh cement paste prepared with normal portland cement, moderate heat portland cement and brastfurnace slag cement.
　The ratio of bound chloride ion was increased of 2 steps, from 1 hour to 1 day and from 3 to 7 days. 30 to 40% of the chloride ion in the mixing water were bound at the age of 1hour to 1day, and 70 to 95% were bound by cement hydrates at the age of 3 to 7 days. The binding of chloride ion before 1 day was done by adsorption to cement hydrates, and that at the age of 3 to 7 days was done by incorporation to Friedel's salts. Brastfurnace slag cement which contains high Al₂O₃, bound greater amount of chloride ions.
　In cement paste prepared with normal portland cement added 2% of SO₃ by gypsum, formation of Friedel's salts was delayed and amount of it was smaller than normal portland cement, consequently ratio of bound chloride ion was smaller than normal portland cement.

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 In the present study, it is investigated to obtain fundamental information on internal cracks in reinforced concrete (RC) members and to evaluate existing structures, by using ultrasonic testing (UT) and acoustic emission (AE) method. In order to apply these to RC structures, small-sized specimens containing cracks were made. A crack width is controlled from 0.15 to 2.0mm. The cracks are evaluated by UT transmitted waveforms. The growth of tensile and shear cracks can be identified by AE parameters.
　The results of the laboratory test are applied to a RC pier of a bridge in which cracks are detected. The transmission method can determine the width and the distribution of cracks in the pier. AE activities under live load are also measured in the pier. The types of the cracking can distinguish between tensile and shear mode by AE parameter analysis.

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 Belite-rich cement (BRC) is thought to be suitable for highly fluid concrete like self-compacting concrete. In this study, the reason why BRC is suitable for highly fluid concrete is investigated. The analysis of the fluidizing mechanisms of superplasticizers was carried out on the basis of the fluidity tests for a combination of two types of cements, normal portland cement (NPC) and BRC, and two types of superplasticizers, β-naphthalene sulfonate type (NS) and polycarboxylate type (PC).
　For each superplasticizer added, 0.48mass% of NS and 0.20mass% of PC, the increase to NPC's paste flow was the same. However, NS produced lower flow in BRC than in NPC, and PC produced higher flow in BRC than in NPC.
　The sulfate ion reduced the PC adsorption on cement particles. Therefore, PC showed higher fluidity in the paste of BRC, with lower alkaline sulfate content, than in NPC paste with higher alkaline sulfate content. In the case of NS, it was necessary to use more to achieve the same fluidity as PC because NS tended to make the specific surface area of paste larger than PC and the dispersing ability was less than PC. There was suitable sulfate content for NS, which was around 0.9mass% as Na₂SO₄, for a high fluidity of paste because NS sorbed onto C₃A competitively with sulfonate ion. Because BRC had a lower alkaline sulfate content, 0.28mass% as Na₂SO₄, BRC paste with NS snowed lower fluidity than NPC paste whose alkaline sulfate content was 0.96mass% as Na₂SO₄.

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 The new artificial lightweight aggregate, which has both higher strength and lower water absorption than ordinary lightweight aggregates, has been developed recently. Furthermore, high performance lightweight concrete containing this aggregate has a lighter weight, a stronger compressive strength, a greater durability, and easier handling than conventional lightweight concrete. The basic properties of the new type of artificial lightweight aggregate, and the fresh and mechanical behavior of the high performance lightweight concrete using this aggregate are reported in this paper.

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 The sintering rate for the initial stage of sintering was expressed as a function of temperature and relative density for Al₂O₃. Parameters in sintering rate equations were determined by sintering experiments under a uniaxial load. After it was confirmed that the remarkable grain growth was not observed in the temperature range of this experiment, sintering rate equations for Al₂O₃ was determined. Calculated sintering rate gave fairly good agreement with the experimental date. Change in relative density during sintering as a function of sintering time were calculated and compared with experimental date. The difference between calculated values and experimental data remained less than 2% in all the cases. Sintering shrinkage predicted with sintering rate equations agreed well with experimental data under a uniaxial load, It became evident that change in density during the initial stage of sintering was able to be predicted for Al₂O₃ with sintering rate equation based on viscoelastic analogy model.

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 Effects of microstructures and additions of secondary phases in sialon ceramics on strength, fracture toughness and fatigue properties were investigated to obtain the composites based on sialon ceramics with high reliability for both rapid fracture and delayed failure. The addition of SiC particles increased the creep resistance at elevated temperature because of decreasing the amount and the thickness of intergranular glassy phase. In-situ-toughened sialon with elongated grains have high fracture toughness and high strength. On the other hand, oxide content in the intergranular phase and grain size affected slow crack growth attributable to the stress corrosion by humidity in air, and fatigue under cyclic loading was remarkably accelerated in the material with coarse grains. SiC whisker in in-situ-toughened sialon improved fatigue properties at room temperature, the creep resistance and the oxidation resistance without decreasing its strength and fracture toughness, because the grain boundary is reinforced by SiCw.

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 The method of British Standard (BS) for mineral aggregate has an advantage that can statistically evaluates the strength of a large number of aggregates in one time. But we could not find any correlation of BS crushing value and strength of an artificial lightweight aggregate, which has high strength and low water absorption, newly produced by Taiheiyo Cement Corporation. By compression, fragments from crushed aggregates nil spaces inside the cylinder that would increases friction between piston and cylinder.
　It is studied a new method to press a large number of aggregates, which array in one layer, and here we call this method as "monolayer loading test". As a result, we could find a good relation between values of monolayer loading test and compressive strength of the aggregate. By this method, we can evaluate the strength of the artificial lightweight aggregate statistically.

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 Recently, permeable or drainage pavement has been attracting interest, because it helps to improve walking and driving safety in rainy weather, and hasten to cultivate. As one of permeable or drainage pavement, the establishment of technique for porous concrete pavement is hoped. This paper describes porous concrete that is high strength and high void ratio, with the inorganic admixture "Road Mix", in stead of polymers. As landscape pavement, when total void ratio is 25%, its target values of compressive strength is more than 15.7N/mm². From relationship between compressive strength and bending strength, 2.63N/mm², is the target value instead of compressive strength, 15.7N/mm². Laboratory tests showed that when the concrete has a more than a 35% m/g ratio, a 22% W/C ratio and a 2.0 C/S ratio, its properties achieved the target values of bending strength. A m/g ratio is a volume ratio, m is a unit volume of mortar which are composed by cement, admixture, fine aggregate and water, g is a unit volume of coarse aggregate. Result of execution test showed that the target values were achieved and surface of concrete was fine, when the concrete has a 42% m/g ratio. From the results described above, the possibility of application of high void porous concrete for landscape pavement use was confirmed. We plan to go ahead with a program including mixture technique of more high void porous concrete, its void ratio is 25%, evaluation of concrete durability.

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 The purpose of this paper is the development of lightweight high bending strength panel. The bending strength properties of honeycomb cellular structure panel were examined. At the beginning, the honeycomb cellular shapes and sizes were examined, we selected a regular hexagonal cell which was thought to be the most useful for getting lightweight, high bending strength panels. Next, regular hexagonal honeycomb cellular panels were made mainly from old corrugated containers (OCC) or rock wool (RW). The specific bending strengths (bending strength / panel density) of these panels were found to be more than 20N/mm². The properties of these panels were superior to standardized fibreboards with regards to bending strength. It was confirmed that the honeycomb cellular structure was effective for getting a lightweight high bending strength panel.

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 In recent years, it becomes more difficult to procure low-sulfur Delayed Oil Coke (DOC) at a moderate price because of the increase of sulfur content of crude oil and the spread of world-wide demands for DOC.
　We have studied flue gas desulfurization (FGD) of the power station exhaust gas in order to keep SOx at the lowest level in case of using low-price high-sulfur DOC.
　As a result of the study, it has been decided to adopt Magnesium Hydroxide Gypsum Process which have both advantages of the Limestone Gypsum process and Magnesium Hydroxide process. The facilities have been installed in our Tsukumi Plant and started in operation in July 1998. After adjustment of running condition, it passed the pre-used examination of Kyushu Bureau of International Trade and Industry in September of that year, and is running satisfactorily. We could get the satisfactory desulfurization performance and good quality of gypsum as by-product, and also attempt the planned reduction of cost.

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 The cement industries is required to restructures environment cleaning function by utilization wastes in Japan. It is necessary to characterizes the incineration ashes, in the view point of recycling rate, physical property, and chemical composition, in order to determination ashes values of Municipal Solid Waste in cements industries. The establishment of experimental condition with consideration of utilization is necessary to use these characterization data.
　In this report, authors propose one research manual of analysis ashes properties. These are, investigation before research, sampling methods, or manufacturing analysis sample. We hope this report is used many cases.

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 The trials of manufacturing metal composites reinforced with ceramics fiber or powder socalled MMC have been done so far. However, due to the facts of poor wettability between aluminum metal and ceramics powder, additionally the need of expensive and large scale high pressure loading apparatus even if dared to try, the technology has not yet been up to the level which enable to manufacture actual parts.
　We, CELANX had introduced fundamental pressureless in filtration process invented by LANXIDE Corporation (research and development company) in USA and made efforts to establish our own industrial technology to manufacture actual products concretely. CELANX must be the first MMC machine parts manufacturer all over the world.
　Volume fractions of ceramic particles into Metal Matrix 20% to extremely high 70% can be achieved on this MMC technology, those can be applied for customers demands of their applications and structural designs. High performances of light weight plus high stiffness, low thermal expansion, high thermal conductivity, high damping and so on are regarded as more attractive than we expected and promoted to apply for many industrial fields.
　The present work describes not only manufacturing processes of MMC, its high performances but also applications and items to be developed in future.

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 Although the procedure for the estimation of the amount of reduction in CO₂ with the individual use of recycled materials as raw materials, fuels or blending materials in the cement manufacturing process has been reported, the estimation procedure in the case where the type of usage of recycled materials is not clear as is in some published data has not been reported in spite of the relative importance of such data. In this report, the assumptions to be used in such a case are examined and the estimation procedure of ecobalance is proposed. With the use of this procedure, 13-16% reduction in CO₂ emission and 87% reduction in the rate of exhaustion of land fill spaces for disposal of wastes are estimated as the results of the use of recycled materials in the cement manufacturing process in Japan.

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