Eco-cement is a new type of Portland cement being developed not only to solve the municipal and industrial waste problem caused by limited availability of landfill sites, but also to contribute to the protection of the environment by providing a complete recycling system of wastes that would otherwise be dumped. This new cement is designed to use municipal waste incinerator ash as up to 50% of raw materials. Combustible wastes like waste oil, plastics, RDF (refuse-derived fuel) also can be used as fuel. Eco-cement consists of the same main components as normal Portland cement (NPC); alite(C₃S), belite(C₂S), calcium aluminate (C₃A), calcium alumino-ferrite (C₄AF) and calcium sulfate. The manufacturing process of Eco-cement is also mostly the same as NPC. Incinerator ash generally contains substances undesirable for cement, such as Cl and a small amount of heavy metals. The metals vaporize in the form of chlorides through the sintering process and are caught as kiln dust in the bag filter. The heavy metals, then, are extracted from the dust through the metal recovery process and delivered to a smelter for refining. This makes the Eco-cement process a complete recycle system for municipal and industrial wastes. Another type of Eco-cement featuring rapid hardening in one hour was also designed. This cement contains 20% of calcium chloro-aluminate (C₁₁A₇･CaCl₂), instead of C₃A. Other main components of this type are C₃S, C₂S, C₄AF and calcium sulfate. This cement is suitable for concrete blocks, wood-fiber board and other non-rebar concrete products.

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 Filler cement which uses limestone powder is noticed as one of energy saving and low environmental loading type. This study deals with the performance of concrete using filler cement which is improved in quality based on the results of previous studies, and the evaluation of ecology balance. Filler cement which is composed of 75wt% high blaine portland cement (3800cm²/g) and 25wt% limestone powder, and ordinary portland cement (3300cm²/g) were prepared. The strength of concrete using filler cement was equivalent to that of concrete using ordinary portland cement without any change in mix proportion except only adding 200ppm triiso-propanolamine to cement. The fluidity of concrete was improved with finess of limestone powder in filler cement. It was confirmed that filler cement and concrete using it was relatively soft in environmental load.

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 Increase of surface temperature by change of land cover is one of the cause of heat island phenomenon. In this study the effect of porous concrete pavement with high void ratio to control an increase of surface temperature was determined by outdoor experiment and numerical simulation in summer season, in comparison with normal concrete and dense asphalt.
　Surface temperature of porous concrete in the experiment was higher than normal concrete but lower than asphalt. Sensible heat from porous concrete to the atmosphere was the middle of those of the two.
　Water storage pavement is the variation of drainage pavement of which the void is filled with water. The simulation showed the effect of water storage pavement that diurnal maximum temperature of the pavement was lower than normal concrete by 3.2℃ when water filled to the surface of pavement. Sensible heat from water storage pavement was a half of that from normal concrete, a quarter of that from asphalt pavement.

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 The zeolite brick is a product made from the waste containing silica and alumina. The process of preparation is as follows;
(1) Wastes are immersed in NaOH solution.
(2) The product is pressed to remove out excess alkali and water, and formed into bricks.
(3) The green body was autoclaved at a temperature of 180℃.
　The autoclaved products were made with various types zeolite such as analcime and Na-P type zeolite.
　In case of high CaO content waste, a well crystallized calcium silicate hydrates is formed. Such formation cause cracking and swelling, which results in a decrease of zeolite brick-s strength.
　Silica, alumina, and calcium are known as basic material used to produce a limesand brick by autoclaving.
　Therefore, it is possible to recycle various wastes containing silica and alumina by using zeolite brick together with lime-sand brick processes.

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 This report is an abridged edition of the final report on the joint research project conducted by National Research Institute of Agricultural Engineering and Taiheiyo Cement Corporation and its associated companies.
　The project theme was to develop the technology on improving subgrade soil and foundation of irrigation reservoir dike by Eco-cement stabilizer.
　Eco-cement stabilizer is consist of Eco-cement and some kinds of inorganic additives, which is a special cement mainly made from municipal solid waste incineration ashes and considered as a kind of environmental-load-reducing cement.
　It was corroborated in the laboratory tests that the soils improved by Eco-cement stabilizer showed superior mechanical properties to those by Blast-furnace slag cement type B and that Eco-cement stabilizer was a non-polluting material.
　Furthermore the results in the field tests supported the properties in the laboratory tests.
　As the results, it was concluded that Eco-cement stabilizer was the effective material to improve subgrade soils and poor foundations.

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 Well-conditioned dewatered cakes of sewage sludge can be used as raw material or fuel for cement manufacturing. However, the amount of cake treated by adding iron chloride and calcium hydroxide as flocculant in sewage treatment plants is severely restricted in cement manufacturing due to its high chloride content.
　In combination of iron compound, the　flocculant, which has been originally developed for the treatment of lake sediment, was applied to the sewage sludge. Compared to the performance of traditional flocculants of iron chloride and calcium hydroxide, the same agglutination and dewatering effects were achieved. The chloride contents in the resultant cake were decreased by at least one half. The above results were demonstrated through a test using middle-scaled dewatering equipment in a sewage treatment plant.

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 Recently, Refuse Derived Fuel (RDF) is focused on because of recycling wastes and reducing dioxin emission and so on. Tsukumi plant of Taiheiyo Cement Corporation is using RDF by Tsukumi-city as an alternative fuel and raw materials for the cement production. RDF includes high content of chlorine. It is important to analyze the chlorine content in RDF for the stable operation of the cement production, because the high content of chlorine exerts a bad influence on the cement production.
　The aims of this paper are the establishment of analytical method for chlorine content in RDF and the estimation of chlorine content in RDF by Tsukumi-city with the method. The method was optimized, according to compare with existing analytical methods for chlorine content. And then, the chlorine content in RDF by Tsukumi-city was analyzed and estimated for each 8 weeks in winter and in summer in 1998. The results are as follows,
　1) The analytical method for chlorine content in RDF has been established.
　2) RDF by Tsukumi-city includes about 1wt% of chlorine.
　3) The chlorine content in RDF by Tsukumi-city dose not show clearly the seasonal variation.

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 Phytoremediation can be defined as the use of plants, including trees, grasses and aquatic plants to remove, destroy or sequester hazardous substances from the environment. It is being investigated and/or used commercially to treat a variety of contaminants in a number of different scenarios. In this review, we explain ten different scenarios for phytoremediation that are phytoextraction, phytostabilization, phytostimulation, phytovolatilization, phytotransformation, phytomining, rhizofilteration, hydraulic barriers, vegetative caps, constructed wetland by showing typical examples, respectively. In the field of phytoremediation research, the pioneering academic research on naturally occurring plant of hyperaccumulating heavy metals has been the direct precursor of today-s research activities. Although heavy metals are still the main subject for phytoremediation, it is believed that phytoremediation has another possibilities to treat organic hazardous compounds. We describe here several compounds that have been successfully remediated by phytoremediation. Finally we present one estimate for worldwide phytoremediation revenues and predictions for coining years. The estimated 2000 U.S. market size is 50-86 million dollars. It is predicted that the U.S. market size will increase rapidly and is close to a doubling of the market in 2002. It is also predicted that the size of the international market including Japan increase rapidly.

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 The dispersing force of polycarboxylate-type superplasticizer (PC) with poly (ethyleneoxide) graft chain has been known to degrade by the sulfate ion in the aqueous phase of concrete. Various material characteristics as well as environmental conditions affect the sulfate ion concentration. Therefore, it is generally very difficult keep the sulfate ion concentration constant. In this study, the active control the sulfate ion concentration in aqueous phase by adding soluble salts such as CaCl₂ and alkaline sulfate has been attempted. The adsorption of PC is able to be controlled by adding salts such as CaCl₂ and Na₂SO₄. The change of PC adsorption ratio directly results in the variation of the dispersing. It is also indicated that ionic strength in the aqueous phase affects the dispersing force of PC.

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 As the note-type PC popularizes, ceramic piezoelectric transformer, used in the power unit for back-light of liquid crystal panels, has been taken notice of. In this paper, the mechanism of ceramic piezoelectric transformer was described after the introduction of historical background. The hard-type piezoelectric material which shows low mechanical loss is suitable for transformer. Because the mechanism of piezoelectric transformer is based on the electrical-mechanical energy conversion and mechanical-electrical energy conversion. The feature of the laminated type piezoelectric transformer was shown with our data after describing the general feature. Then, the data of life test suggests that the breakdown probability for 40,000 cycles of ON/OFF is low, 3.8×10^-5. The concept of the electrical control and the electrical circuit for piezoelectric transformer was shown at the end.

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 Mechanical properties of cement as a powder, such as packing property, flowability and adhesive property, are reviewed on the following points.
(1) Relation with process operation
(2) Measuring technique
(3) Factors affecting the observed values
(4) Controlling methods
(5) Application to system design
　Furthermore, a few recent topics relating to the mechanical properties of cement are introduced.
　It is concluded that the mechanical properties of cement have several different aspects, and any single value cannot represent all of them. To be useful in practice, the appropriate measuring technique should be chosen under consideration of the dominating mechanism that controls the target process or operation.

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