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Abstract

In recent decades, the utilization of mineral and chemical admixtures in concrete technology has led to changes in the formulation and mix design which has, in turn, made the concrete stronger and more durable. Light weight concrete (LWC) is an excellent solution in terms of decreasing the dead load of the structure, while self-compacting concrete (SCC) eases the pouring and removes construction problems. Combining the advantages of LWC and SCC is a new field of research. Considering its light weight of structure and ease of placement, Light-weight self-compacting concrete (LWSCC) may be the answer to the increasing construction requirements of slender and more heavily reinforced structural elements. Twenty one laboratory experimental investigations on the mix proportion, density and mechanical properties of LWSCC have been published in the last 12 years and these are analyzed in this study. The collected information is used to investigate the mix proportions including the chemical and mineral admixtures, light weight and normal weight aggregates, fillers, cement and water. Analyzed results are presented in terms of statistical expressions. It is very helpful for future research to choose the proper components with different ratios and curing conditions to attain the desired concrete grade according to the planned application.

8. Conclusion

LWSCC is new type of concrete that combines the advantages of both LWC and SCC. However, publications about mix design, mechanical properties, component materials and the curing condition are very rarely found in the literature. This study has collected almost all the published investigations with sufficient details in terms of country and year of research, mix proportions, components, curing condition, density and compressive strength of LWSCC, in order to extract worthwhile conclusions for researchers and practitioners. Analyzing 114 LWSCC mix designs of 21 recent laboratory investigations from 2001 to 2013, the following conclusions can be reached: Compressive strength: different ranges of low and high compressive strength are achievable in LWSCC. In this investigation, 53 and 34% of the mix designs give the compressive strength in excess of 32 MPa and 40 MPa respectively. Aggregate: both types of light and normal weight aggregates have been used in the mixes; however 70% of mixes do not apply the normal weight coarse aggregate to produce LWSCC. Admixtures: different types and ranges of mineral and chemical admixtures (super plasticizer, air entraining agent and viscosity modifying agent) have been used in the mixes to attain the desired flowability and the fresh and hardened properties. Powder: fillers and cement are two types of powder applied in all LWSCC mix designs. The variation of filler types is more than that of the cement types in the LWSCC mix designs. Mix proportions: some key notes on the mix design of LWSCC are presented as follows: - Just 30% of the mixes use the normal weight coarse aggregate, and the maximum weight ratio of this type of aggregate in the mix volumes is 38.6%. Water/cement and water/total powder ratios vary between 0.25–0.85 and 0.25–0.5 respectively. - Different ranges of chemical admixtures have been used in the mixes, however despite the inclusion of super plasticizer in the mixes; the air entraining agent and viscosity modifying agent are not used in all LWSCC mix designs. - The weight ratio of cement, mineral powder and the combined weight of cement and mineral powder to the mix weight vary between 9.44 and 29.77%, 1.26 and 15.79% and 18.98–42.53% respectively in all the LWSCC mix designs.