الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Fines are specially selected, natural or artificial inorganic fine materials, which improve the physico-chemical and mechanical properties of concrete and mortar. They can be inert or have slightly hydraulic or pozzolanic properties. They cause no appreciable increase of the water demand, in addition to not impairing the resistance of the concrete or mortar to deterioration in any way or reducing the corrosion protection of reinforcement. Lime clay powder is a by-product of sugar industry that can be used as a natural inorganic filler in concrete and mortar depending on its pozzolanic activity, fineness and calcium carbonate content. The objective of this investigation is to study the effect of lime clay powder addition on the properties and durability of concrete and mortar. The test program was divided into two phases. In the first phase, the test program was arranged to determine the effect of lime clay powder content and cement type and content on the properties and durability of concrete and mortar. In the second phase, the test program was arranged to determine the effect of admixtures -silica fume and superplasticizer- on the consistency, mechanical properties and water permeability and absorption of concrete. The results show that lime clay concrete and mortar present satisfactory workability and strength; the strength significantly increased at early age and slightly decreased at later ages. By using 10% of lime clay powder (by weight of cement) concrete exhibited the optimum mechanical properties increase. However, the consistency of mortar and concrete decreased by no more than 12 and 15%, respectively. At 1 and 3 days age, mortar induced compressive strength gain of 13 and 6%, respectively, and concrete indicated compressive strength gain of 18 and 8%, respectively. However, the strength decline does not exceed 7% at 28 days age. Increase in the early strength of concrete is mainly attributed to the acceleration of cement hydration. The mineralogical composition and fineness of Portland clinker affect lime clay powder performance. The addition of lime clay powder to clinker having high LSF (high C3S) and high fineness enhanced predominantly early strength, however, cements with high C3A and high fineness seem to be more appropriate for reducing the permeability properties of lime clay powder concrete and mortar. In addition, lime clay powder concrete containing low cement content indicated relatively high increase of early age strength. Lime clay powder mortar and concrete indicate competitive improvement for some aspects of the durability. The addition of 15% lime clay powder in mortar increases the resistance of sulfate attack by about 35% after two years through preventing the transformation of ettrigite to sulfoaluminate. Besides, lime clay powder decreases the water absorption and permeability of concrete; relative water absorption and permeability of 74 and 82%, respectively, is achieved in 15% lime clay powder concrete. Other key for enhancing the consistency, mechanical properties and water absorption and permeability of lime clay powder concrete is silica fume and superplasticizer. Firstly, silica fume addition enhances the concrete strength; the addition of 10% silica fume to 10% lime clay powder concrete exhibited a strength gain of 7, 7 and 29% at 1, 3 and 28 days, respectively. Furthermore, water absorption and permeability decreased by 20%. Secondly, superplastisizer has an important role in enhancing lime clay powder workability; the dose of 1% superplastisizer of cement improves the consistency by 100%, averagely.