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SP-178 This Symposium Publication contains the proceedings of the Fourth CANMET/ACI/JCI International Conference held in Tokushima, Japan, in June 1998. Sixty-two refereed papers were accepted for presentation at this conference and for this publication.

Canada Centre for Mineral and Energy Technology (CANMET) has an ongoing project dealing with the role of supplementary cementing materials in concrete. As a part of this program, a new type of concrete known as high-volume fly ash concrete has been developed. In this type of concrete, the water and cement contents are kept very low, i.e. about 115 and 155 kg/n?, respectively, and the proportion of low-calcium fly ash is about 56 per cent of the total cementitious materials. This type of concrete has excellent mechanical properties and durability characteristics. The objective of this study was to investigate the application of the high-volume fly ash system to the production of structural lightweight concrete. In this study, high-volume fly ash concrete mixtures were made using ASTM Type I portland cement, fly ashes from sources in the U.S.A. and lightweight coarse aggregates from four different producers, three from the U.S.A., and one from the U.K. A reference concrete mixture without fly ash was also made for comparison purposes. A large number of test specimens were cast to determine the mechanical properties and durability characteristics of the concrete. The test results show that the structural high-volume fly ash concrete had mechanical properties similar to those of the reference concrete. The fly ash concrete generated significantly less heat of hydration, and showed noticeably better resistance to chloride-ion penetration than the reference concrete of similar 2%day strength. All concretes investigated demonstrated an excellent resistance to the freezing and thawing cycling

Coincident with the investigation of the utilization of Mount Pinatubo ejecta on the production of paving blocks for sidewalks, parking areas and other footpaths, a study on the durability of the blocks was also undertaken. Blocks with a plan area of 1OOmm x 200mm and a thickness of 85mm were prepared with three mixture proportions. The mixture proportions were prepared to represent three strength levels. Specimens from each mixture were subjected to both natural and accelerated weathering conditions. The compressive strength in accordance with ASTM C 936 and the abrasion resistance in accordance with ASTM C 779 were determined for various ages. The test results as shown in this paper for the durability parameters selected, show favorable long term properties of the paving blocks.

This study proposes a new method for a process development based on specific planning and use of experiments. The ‘Statistical Design Of Experiments’ method comprising the selection of experiments in manner where the results derived from these experiments can be used for the calculation of values to be analysed. Ash produced from the Incineration of Municipal Solid Wastes requires to be solidified and stabilised prior to landfilling. MSWI fly ash is a powdery material. It comprises hydraulic and toxic elements. Ground granulated blast furnace slag is a suitable hydraulic binder to stabilise this ash and MSWI ash can activate the slag hydraulicity. A preliminary study was undertaken on artificial MSWI ash to analyse the influence of the variation of the content of (Ca(OH)2 , CaCIOH, CaS04 ) ash components, while taking into account their interactions effects. It was demonstrated that CaClOH content significantly influences the behaviour of the material. Empirical laws were also developed to determine the mechanical and physical behaviour of mixtures of industrial MSWI ash and slag. The parameters of these models were A/S, W/(A+S), and the water temperature. Then, using the various models developed, an optimum formulation of the MSWI ash and slag mixture was developed, which fulfils the requirements of French Regulations.

These days, large and complicated concrete structures are mushrooming. Performance requirements include not only functionality and strength but also aesthetics. From a material viewpoint, it can be said that the requirements for high performance concrete include : adequate flowability, strength and durability. This study shows that combining fly ash and silica fume as mineral admixture is an effective way to improve the properties of concrete. The influence of fly ash and silica fume on fluidity and strength of mortar and concrete was experimentally investigated. Five fly ashes, classified into 3 types obtaining from each hopper of precipitator, were used and constituted 60, 70, 80 and 100% by weight of the total amount of mineral admixture. In this study, flowability was investigated by measuring the flow/slump flow while keeping the chemical admixture-binder ratio within a pre-determined range. Strength was evaluated by compressive strength tests at 14, 28 and 91 days. The relationship between mineral admixture properties and mortar/concrete properties were studied. As a result of the tests, higher strength and adequate flowability were obtained by combining fly ash and silica fume.