تقييم استخدام الرمل النهري في إنتاج الخرسانة

الملخص EN

Rivers and large channel , training and digging out works generate huge amounts of river's sand.

The research deals with the use of river's sand as partial replacement of regular sand to produce concrete.

The effect of partial replacement on the properties of fresh concrete (slump of mixes) and the properties of hardened concrete (compressive strength) have been studied.

Many concrete mixes were prepared with use of river's sand as partial replacement of regular's sand rated (from 5% to 50%) and reference mix which is prepared without river's sand.

Those mixes of concrete was prepared with selective mix proportions of 1:2:4 (1 cement : 2 sand : 4 gravel) by weight and water/cement ratio of 0.55.

The results have shown that the compressive strength of concrete increased with the increase of sand replacement rate for particular amount with the slump reducing.

The maximum increase in the compressive strength 23% is found when the replacement rate is 35% with the slump decrease up to 57% in comparative with the reference mix.

The results indicate that the increase of water/cement ratio by 4% in comparative with the reference mix for the mix have 35% river's sand make the slump of the mix is approximately the same of reference mix without significant decreases in the compressive strength in comparative with reference mix.

The slump of mix which have river's sand 35% can be increased also, approximately to the same amount of the reference mix with same water/cement ratio of reference mix by using concrete mix of 1:1.5:4.5 with the increase of compressive strength equal to 20% in comparative with reference mix.