Reactive Silica Sand Powder Concrete (RSSPC) Uniaxial Compressive Strength Investigation

Hossein Kabir,Mojtaba Sadeghi

doi:10.11131/2017/101230

Abstract

Nowadays, high-strength concrete is an integral part of so many high-rise buildings. In accordance with the ACI 211.1-91 the mixture aggregate size should be less than 0.5 inches in order to achieve a uniaxial compressive strength greater than 9000 psi. On the other hand, finding a suitable aggregate grading distribution of concrete mix design is a big deal; hence force, the authors propose a mix proportion with no coarse aggregate still withstand enough strength. Silica sand powder concrete is a type of concrete with actually no coarse material in its own composition. In this concrete, the only aggregate is silica sand powder in which its size is less than 150 μm that is very small in size. According to the ASTM C 33, this concrete is classified as an ultra-fine aggregate concrete. The research interest is to find the compressive strength of this particular concrete under different conditions of curing and consolidation to compare each approach with each other. In this article, the young concrete specimen was compacted with a pressing or vibrating process. It is worthwhile to mention that to show the role of temperature on the curing process, the concrete specimen was cured both in 20∘C lime water or autoclaved in 90∘C oven.

Highlights

Dates Received 13 May 2016 Accepted 11 December 2016The main factors that increase the compressive strength of concrete is using low water to cement (w/c) ratio, increasing fine fillers, compacting wet concrete and removing voids (Brandt A.M. 1998) [4]
The basic principles for the development of Reactive Silica Sand Powder Concrete (RSSPC) are listed as follows: 1. There is no coarse aggregate in this concrete and the maximum aggregate size is less than 150 μm
These results are different from the Reactive Powder Concrete (RPC) being considered by Richard P. and Cheyrezy M. (1995) [11] in which they found that in RPC pressing the young age concrete increases the uniaxial compressive strength by 38%; in the present RSSPC with the same mix design except its aggregate material/size, as the results suggest, the pressing process would reduce the specimen strength by 4% in the normal curing and 2% in the autoclaved process or thermal accelerated curing

Summary

Introduction

The main factors that increase the compressive strength of concrete is using low water to cement (w/c) ratio, increasing fine fillers, compacting wet concrete and removing voids (Brandt A.M. 1998) [4]. It should be noticed that silica powder is ultra-fine aggregate sand, so it has a large effective area; enough cement should surround aggregates properly. Using this great amount of cement demands a high ratio of W/C, but this ratio must be lowered because of the concrete shrinkage; the role of superplasticizer is so important. In former studies, the compaction removes the voids and extra water from the wet concrete and increases the compressive strength, but in RSSPC, as the results show, it has a converse consequence (J.L. Amorós et al 2008; Konstantin Kovler et al 2011) [3, 9]

Experimental Program

Results

Conclusions