The Compressive Strength of High-Performance Concrete and Ultrahigh-Performance

E. H. Kadri,S. Aggoun,A. Kaci,S. Kenai

doi:10.1155/2012/361857

Abstract

The compressive strength of silica fume concretes was investigated at low water-cementitious materials ratios with a naphthalene sulphonate superplasticizer. The results show that partial cement replacement up to 20% produce, higher compressive strengths than control concretes, nevertheless the strength gain is less than 15%. In this paper we propose a model to evaluate the compressive strength of silica fume concrete at any time. The model is related to the water-cementitious materials and silica-cement ratios. Taking into account the author's and other researchers’ experimental data, the accuracy of the proposed model is better than 5%.

Highlights

IntroductionThe use of silica fume in combination with a superplasticizer is a usual way to obtain high-strength concretes
The use of silica fume in combination with a superplasticizer is a usual way to obtain high-strength concretes.The improvement of mechanical properties of concretes with silica fume accounts for the increasing consumption of this admixture in concrete
Between one (t1 ) and about ten days, the compressive strength R increases linearly according to the logarithm of time t

Summary

Introduction

The use of silica fume in combination with a superplasticizer is a usual way to obtain high-strength concretes. The improvement of mechanical properties of concretes with silica fume accounts for the increasing consumption of this admixture in concrete. Apart from mechanical properties, the durability of high-performance concretes concerning the most common harmful ions (sulfate, chloride, and seawater) is improved; the reduction of permeability which is due to the more compact microstructure of concrete slows down the diffusion of ions. Various authors point out some drawbacks regarding the use of silica fume in concretes. The loss of plasticity during the production of concrete and the great sensitivity to plastic shrinkage during the initial curing are the most important. Researchers seem to disagree about the interpretation of the exact role silica fume plays in the increase of mechanical strengths

Methods

Results

Conclusion