No abstract

Concrete is a versatile and cost-effective building material whose properties are influenced by age, curing condition, and installation. A number of studies deduced that there should be an association of benefits encouraged the use of partial replacements of cement seems to improve strength and durability properties of concrete. This paper presents a framework for feasibility assessment and determination of optimum percentage of rice husk ash (RHA) replacement. Five mix plans with RHA replacing ratio of 0-20% and constant micro-silica value by 10% were prepared. Tests results indicated that compressive strength increased by 20% with an increase in RHA up to 15%. The similar trend was observed in mix designs made of cement replaced by RHA up to 20% in water absorption coefficient measurement. Higher chloride ion penetration was observed in mix designs containing 25% RHA compared to that of conventional concrete. Mixes developed a slightly higher impact resistance than the control mix.

With increasing trends towards the broader usage of concrete and warning depletion of natural resources of aggregates, it seems reasonable to find mineral additives or binding materials of different types as ingredient of concrete. Accordingly, wide usage of light weight concrete lies on some main structural applications as reduction of total dead, seismic loads, environmental pollution, and labour cost. This paper tries to investigate the properties of light weight blended concrete containing lime stone powder (LP), micro-silica (MS), pumice, and leca in various proportioning rateing as a partial replacements of cement. Utilization of these additives on the compressive strength, tensile strength, water absorption coefficient, acid resistance, and impact resistance examined experimentally in various curing conditions at the ages of 7 and 28 days to evaluate the combined effect of micro-silica and lime stone incorporation on strength and durability properties of light weight concrete, along with introduction of optimum replacements. For this purpose, 10 lime-stone based concrete mixtures were prepared with proportions from 0 to 20%, and constant values of 10% micro-silica and w/c ratio. From the results, it was indicated that addition of lime stone powder in concrete reduces short-term properties as well as the compressive strength. Optimum levels of powder replacements can serve as sustainable and durable concrete, also environmental and economic benefits.