The Effect of Superplasticizer and Pozzolan on the Fresh and Hardened States of Crushed Limestone Sand Concrete

Abstract The primary goal of this paper is to investigate the effects of a superplasticizer and the addition of pozzolan on the fresh and hardened states of crushed limestone sand concrete. On the one hand, it's a matter of proposing concrete mixes that replace natural sand (river sand) with crushed sand, and on the other, it's a matter of attempting to improve the qualities of the concrete thus produced. In this respect, three variants of crushed limestone sand have been proposed from the same quarry, including: sand without modification (in its initial state), sand sieved through a sieve of 0.16 mm size and washed sand; further for the comparison, natural sand is used as control. A superplasticizer and a pozzolan addition were also used for better performance.The results show that the crushed sand concrete mixes produced have mechanical strengths comparable to natural sand concrete mixes. Best mechanical strengths are those of concrete with a percentage of 12% of fine particles. Beneficial effects have been observed following the use of the superplasticizer and pozzolan, thus giving improved performance to crushed sand concrete both in its fresh and hardened states.