Efficiency of Sodium Polyacrylate to Improve Durability of Concrete under Adverse Curing Condition

Abstract

The conventional external curing process requires supply of large amount of water in addition to mixing water as well as strict quality control protocol. However, in a developing country like Bangladesh, many local contractors do not have awareness and required knowledge on importance of curing which often results in weaker concrete with durability issues. Moreover, at times it is difficult to maintain proper external curing process due to nonavailability of water and skilled laborer. Internal curing can be adopted under such scenario since this method is simple and less quality intensive. Usually, naturally occurring porous light weight aggregates (LWA) are used as internal curing agent. However, naturally occurring LWA are not available in many countries like Bangladesh. Under these circumstances, Super Absorbent Polymer (SAP) can be utilized as an alternative internal curing agent. In this study, sodium polyacrylate (SP) as SAP has been used to produce internally cured concrete. Desorption isotherm of SP has been developed to investigate its effectiveness as internal curing agent. Test results showed that internally cured concrete with SP performed better in terms of both strength and durability as compared to control samples when subjected to adverse curing conditions where supply of additional water for external curing was absent.

Optimum Proportion of Masonry Chip Aggregate for Internally Cured Concrete

“…One is by using lightweight aggregates (LWA) and other way is using super absorbent polymers (SAP). Both LWA and SAP absorb water before mixing and later, desorb absorbed water during curing (Mather 2004;Manzur et al 2015). When LWA is used as internal curing medium within concrete, usually small amount is required to supply the additional water (Bentz and Weiss 2010).…”

“…Therefore, benefits of internal curing can be summarized as enhanced hydration of cement, higher strength development, reduction of autogenous shrinkage and cracking, decrease in permeability, and improvement of durability etc. (Bentz et al 2005;Manzur et al 2015;Bentz and Weiss 2010;de Sensale and Goncalves 2014;Chun and Kim 2015;Zou and Weiss 2014;Zou et al 2015;Geiker et al 2004). The impact of internal curing begins immediately during the initial hydration of the cement, with benefits that are observed at ages as early as two days.…”

Properties and Applications of Acrylates

“…Sodium polyacrylate (NaPA), also named as poly (sodium prop-2-enoate), presents the molecular formula (C 3 H 3 NaO 2 ) n . NaPA is a sodium salt of polyacrylic acid with broad application in consumer products, and structural engineering [26]. Though it is soluble in water, when processed into a chemically crosslinked polymer hydrogel, it would swell greatly in water [27].…”

“…NaPA and other derivatives of polyacrylic acid have varied commercial and industrial applications: animal care (pet pads, horse urine odor absorbing materials, drown-free water source for feeder insects); topical health (paper and disposable diapers, sanitary wares and napkins); industry (waste liquid control, drilling fluids, concrete protections). environmental protection (geo-textiles for road constructions, anti-flood bags, excreta collection bags and containers); structural engineering application of concrete structures with sodium polyacrylate serving as an internal curing agent and exhibiting enhanced durability and strength performance [26]; biomedical field for drug delivery applications in ocular, nasal, buccal, gastrointestinal, epidermal and transdermal drug delivery system due to their biocompatibility and similarities with living tissues in the pharmaceutical industry [27]; other products such as wire and cables, water blocking, artificial snows, hot/ cold gel packs, urine bags, toys, thickening agents, fragrance carriers, fire-retardant gels, anti-fogging packing materials and waterbeds.…”

Concept: fluorescent and waterlock-expansion material to detect potential of corrosion on metal substrate

“…It is commercially used in the agricultural, food and even in the pharmaceutical fields, mainly for absorbing fluid. It has many desirable properties such as being non-toxic to living organisms, biodegradable and exhibits hydrophilic properties that are environmentally friendly (Behera and Mahanwar, 2019; Manzur et al , 2015). The expansion of SP in the coating will act as an indicator for when water penetrates the top coat.…”