Probabilistic and experimental investigating the effect of pozzolan and Lumachelle fine aggregates on roller compacted concrete properties

摘要

Lumachelle stones, which are produced by marine sediments widely available in most coastal areas, can be considered as one of the aggregates replacements in roller compacted concrete (RCC). This study aims to evaluate the applicability of Lumachelle as fine aggregates in RCC that contains pozzolan. Three series of mixtures A, B, and C were designed based on the "dimension reduction prediction method" (DRPM). Mixes contained different water/cement ratios (W/C), varied quantities of pozzolan, and different amounts of Lumachelle fine aggregates as a replacement for the standard fine aggregate. Compressive strength, water absorption, under-pressure water penetration depth, and elasticity modulus tests were done on the specimens. Probabilistic performance evaluation and sensitivity analysis were also carried out based on the Monte Carlo simulation, the score function approach, and the DRPM. Experimental results have revealed that if optimum moisture content is calculated and used, specimens with different percentages of Lumachelle fine aggregates will have strengths close to those prepared with standard aggregates. It can be concluded, therefore, that Lumachelle fine aggregates can be used in the RCC through appropriate control of the W/C-Pozzolan ratio; Pozzolan reduces water penetration in mixes effectively causing the enhancement of concrete durability. The probabilistic evaluation results also show that the structure will have an appropriate degree of safety if an optimum moisture content is used and the construction process is controlled. Reliability sensitivity result confirms that among different random variables considered in the analysis, Lumachelle fine aggregates had the least effects on the failure of this type of concrete. (C) 2017 Elsevier Ltd. All rights reserved.