The Properties of fly ash based controlled low strengh materials

Controlled low strength and typically has a load carrying capacity much higher than compacted soils, but it can still be excavated. In this study, a mixture of Soma B fly ash, crushed limestone powder (filler) and a low percentage of pozzolana cement has been tried in different compositions. The weight of cement (TÇ 32.5) was kept constant for all mixes as a 5% of fly ash weight. The amount of mixing water was chosen to provide optimum pumpability by determining the spreading ratio of CLSM mixtures using flow table. The mechanical and physical properties of CLSM mixtures such as ; compressive strength, flexural and splitting tensile strength, direct shear, modulus of elasticity, coefficient of permeability, water absorption by capillarity, freezing and thawing by vacuum saturation, durability in different temperature and humidity condition, thermal conductivity, EP toxicity have been investigated by a series of laboratory tests. On the other hand, chemical durability of CLSM mixtures in aggressive environments such as salt, sulfates, and various types of acids solutions was also investigated. The test results indicated that CLSM mixtures have superior mechanical and physical properties than the compacted soils. Besides, these materials are more durable in many situations than the normal concrete when subjected to the salt, sulfates and acids' solutions due to the high content fly ash.