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Research Article Open Access

Effect of nanosilica on drying shrinkage and creep properties of cement concrete

Lincy Varghese1*, VVL. Kanta Rao2, Lakshmy Parameswaran3

1Academy of Scientific and Innovative Research- Central Road Research Institute, New Delhi 110025, India

2CSIR-Central Road Research Institute, New Delhi 110025, India

3CSIR-Central Road Research Institute, New Delhi 110025, India

Adv. Mater. Proc., 2017, 2 (1), 56-60

DOI: 10.5185/amp.2017/113

Publication Date (Web):01 January 2017

Copyright © IAAM-VBRI Press

Abstract


Abstract

The microstructure and time dependent properties of nanosilica (nS) added high performance concrete (nS-HPC) were investigated, and a comparison of these properties with those of microsilica (mS) added high performance (mS-HPC) concrete and a reference concrete (RefCon) are presented. 3% colloidal nS and 7.5% powder mS were used to make nS-HPC and mS-HPC, respectively. The scanning electron microscopic image of the 90 days’ nS-HPC revealed that the quantity of Ca(OH)2 present was almost negligible and the concrete attained a finer and compact microstructure with finer C-S-H as compared to that of other two concretes. The creep and drying shrinkage of the nS-HPC were found to be higher than those of RefCon and mS-HPC. However, the observed drying shrinkage of all the concrete mixes was found to be conforming with the estimates made from Indian Road Congress (IRC):112-2011 model, while on the other hand, the creep coefficients of mS-HPC and nS-HPC was found to be higher than the corresponding estimated creep coefficients, and the same were found to be higher by 13.3% and 18.2%, respectively, at 100 days. The increase in drying shrinkage and creep of both the high-performance concretes (HPC) than that of RefCon may be attributed to higher amounts of gel water present in the finer C-S-H produced due to pozzolanic action. The results from the study indicates suitability of nS-HPC for construction of bridge structures. Copyright © 2017 VBRI Press.

Keywords


Nanosilica, microsilica, microstructure, drying shrinkage, creep.