Eur. Phys. J. Plus (2016) 131: 28
https://doi.org/10.1140/epjp/i2016-16028-4

Regular Article

An empirical model to estimate density of sodium hydroxide solution: An activator of geopolymer concretes

¹ CACR, SRM University, Kattankulathur 603203, 603203 (Ex-SERC), Chennai, Tamilnadu, India
² Department of Civil Engineering, SJCE, Mysore, 570006, Karnataka, India
³ Department of Chemistry, SRM University, Kattankulathur, 603203, Chennai, Tamilnadu, India
⁴ School of Physical Sciences and FemtoTechnology (Applied Energy Resource Divisions), SRM University, Kattankulathur, 603203, Chennai, Tamilnadu, India
⁵ Postgraduate & Research Department of Physics, Thiru, A. Govindasamy Arts and Science College, Tindivanam, 602004, Tamilnadu, India

^* e-mail: s_nithu59@rediffmail.com

Received: 20 June 2015
Accepted: 14 December 2015
Published online: 3 February 2016

Abstract

Geopolymer concrete is zero-Portland cement concrete containing alumino-silicate based inorganic polymer as binder. The polymer is obtained by chemical activation of alumina and silica bearing materials, blast furnace slag by highly alkaline solutions such as hydroxide and silicates of alkali metals. Sodium hydroxide solutions of different concentrations are commonly used in making GPC mixes. Often, it is seen that sodium hydroxide solution of very high concentration is diluted with water to obtain SHS of desired concentration. While doing so it was observed that the solute particles of NaOH in SHS tend to occupy lower volumes as the degree of dilution increases. This aspect is discussed in this paper. The observed phenomenon needs to be understood while formulating the GPC mixes since this influences considerably the relationship between concentration and density of SHS. This paper suggests an empirical formula to relate density of SHS directly to concentration expressed by w/w.