Investigation on Concrete Properties for Nano Silica Concrete by using Different Plasticizers

Abstract

This paper presents results of the optimal dosage levels of polycarboxylate-based (PSP) (0.4 and 0.8%) and naphthalene-based (NSP) (0.8 and 1.6%) super plasticizers and different water to binder (w/b) ratios (0.4 and 0.45 ) that produce an adequate balance between strength and workability for concrete containing nano-SiO2 (NS) of 1%, 2%, and 3% as cement replacement. These results indicate that For two types super plasticizers mixes. Increasing the w/c ratio from 0.40 to 0.45 increased the slump of all mixes. Either those containing polycarboxylate or naphthalene sulphonate super plasticizer or the control mixes. For polycarboxylate super plasticizer mixes. Decreasing the w/c ratio from 0.45 to 0.40 increased the compressive strength of all mixes. Either those containing polycarboxylate super plasticizer. For naphthalene sulphonate super plasticizer mixes. Increasing the w/c ratio from 0.40 to 0.45 increased the compressive strength of all mixes. Either those containing 0.8 % naphthalene super plasticizer or the control mixes. While decreasing the w/c ratio from 0.45 to 0.40 increased the compressive strength of all mixes. Either those containing 1.6 % naphthalene sulphonate super plasticizer. the use of (1.6 %) sulphonated naphthalene super plasticizer (NSP) with 0.4 w/c ratio reached a gain in strength equivalent to the  use of  (0.8 %) polycarboxylic super plasticizer (PSP) for mix containing 3 % nano silica . the use of (1.6 %)  naphthalene super plasticizer (NSP) with 0.45 w/c ratio reached a gain in strength equivalent to the  use of  (0.8 %) polycarboxylic super plasticizer (PSP) for mix containing 2 % nano silica.

Keywords: Nano silica, concrete, plasticizers, workability, strength.