Effect of Alkyl Sulfonates on Freezing Resistance of Cement Mortars

Abstract

Use of alkyl sulfonate fractions (with overall hydrocarbon chain-length range of Cg-C,) as admixtures to improve the freezing resistance of Portland cement/sand mortars was studied.Alkyl sulfonates were synthesised from hydrocarbon mixtures obtained by polyethylene waste pyrolysis. They act as air-entraining agents but do not show plasticising effect. All of the three different fractions improve freezing resistance but higher than 9% air contents are detrimental to the strength values. The best compromise is the fraction Cg-C,y in 0.02% amount that raises the freezing resistance by 22-28% as estimated from the values of the dynamic modulus of elasticity measured after 200 freezing/thawing cycles. Under these conditions, the bending and compression strength retain not less than 90% of the values measured for the reference mortar after a six-month hardening period.

Effect of Alkyl Sulfonates on Freezing Resistance of Cement Mortars

“…The values of bending strength decreased by 5.4 and 9.5% (28-day hardening time) and by 6 and 17% (6-month hardening time) for 0.02 and 0.04% admixture amounts, correspondingly. The reductions in the compression strength values were by 9 and 20% (28-days) but by 8 and 18% after six-month hardening time.…”

Utilization of Polymeric Wastes

“…These fractions were used for alkylsulphonate synthesis [s]. To study the effect on the strength properties of cement mortars, alkylsulphonates were added in amounts from 0.02 to 0.2% of cement to 1/3 and 1/6 cement/sand mixtures [6]. The effects determined were the rate of air-entrainment, changes in volume mass and bending strength.…”