Replacement of natural sand in mortar by river sand: Mechanical properties

Abstract

The high cost of natural sand in some countries cause to the engineers and researchers to investigate the possibility and feasibility of using other materials to be used as a fine aggregate in concrete mixes. This work aims to provide a better understanding of the mechanical behavior of mortar under loading (compression, direct tension and flexural moment). In Iraq, there are many cities placed along the Tigris and Euphrates, therefore can be obtained a lot of quantities of river sand that result from cree and clean these rivers which is considered a cheap prices material, it is used in agriculture only. The most of natural sand in Iraq contains high sulfur trioxide (SO3) which is exceed the Iraqi Standard Specifications [IQS No. 45, 1984], it is (0.5 %). This work explains the influence of river sand on the mechanical behavior of mortar which replacement of natural sand. Four groups of specimens have been realized within a water cement ratios of 0.48, 0.52, 0.58 and 0,6. One group is considered as reference: these specimens without river sand, natural sand only. Other groups have been river sand that replacement of natural sand of 25, 50 and 75 %. All manufactured specimens have the following dimensions for cubes (50 * 50 * 50 mm), prisms (40 * 40 * 160 mm) and bon dog (25 * 28 * 70 mm). In this work, some tests are used for materials and specimens for examples sieve analysis and flow test for materials. Compression test, flexural test and bon dog test have been designed for specimens. Finally, the experimental results are presented in relationships, histogram and tables between mechanical properties and the replacement of river sand. The results show the effect river sand on the mechanical properties positively until 25 % but this this behavior becomes negatively when this value becomes higher than 25 %.