Investigation of properties of durability and mechanical of self compacting structural lightweight concrete

Lightweight concrete (LWC) is a kind of special concrete that is used for last five decades in structures. The biggest advantage of LWC is to decrease death weight of structure. But the biggest problem is difficulty of workability since lightweight aggregates are porous materials with high water absorption rate. Self compacting concrete (SCC) is also a special concrete that can fill all section by means of its own self-weight and have highly strength and durability properties and with density 2300-2400 kg/m3. If lightweight aggregates are used to produce self compacting concrete, it is named as self compacting lightweight concrete (SCLWC) and SCLWC may be a good alternative concrete type especially in earthquake area. There are good advantages of both concrete type, LWC and SCC, to be able to cover their disadvantages. Moreover Turkey has large reserve of lightweight aggregate like perlite and pumice.In this study, basaltic pumice and perlite aggregate was used to produce SCLWC. The effects of gradation, powder type and aggregate type on durability and mechanical properties were investigated. In addition two different curing regimes were applied on specimens. Silica fume, fly ash, perlite and pumice dusts were used as viscosity agent with different rates. Optimum rates of those powder were determined for both mechanical and durability properties of SCLWC. Compressive and flexural tensile strengths were investigated as the mechanical properties. Freeze-thaw cycled, high temperature, accelerated carbonation and sulfuric acid experiments were carried out to determine durability properties. In addition, water absorption, capillary water absorption, apparent porosity and permeability were investigated. As a result of experiment, SCLWC could have been produced with basaltic pumice and perlite aggregates. The dry unit weights and compressive strengths of the SCLWC prepared are 1700?1900 kg/m3 and 50?60 MPa respectively. The results of experimental studies showed that double mineral admixtures were much more satisfactory than other approaches for SCLWC. In water curing, SCC was showed better performance than SCLWC. However, the mechanical and durability properties of SLWC were not affected as much as SCC with river aggregate from air curing.