Effects of a carboxylic acid/sulfonic acid copolymer on the material properties of cementitious materials

The effects of a carboxylic acid/sulfonic acid copolymer (PMAMP) on the properties of mortars or concrete made with Type I Portland cement were investigated. PMAMP was prepared from methacrylic acid and 2-acrylamido-2-methylpropane sulfonic acid (AMP) in a basic condition through a free radical polymerization. The results indicate that PMAMP with the AMP content of 20–60%, and a weight-average molecular weight (MW) of about 5 × 104, is effective in dispersing cement particles and the resulting mortars or concrete show good fluidity or workability. Besides, PMAMP with higher molecular weigh is more capable of maintaining the workability along with elapsed time. Compared with a commercial sulfonated naphthalene formaldehyde superplasticizer (SNF), PMAMP appears to be more effective in promoting concrete workability and preventing the slump loss. Finally, concrete incorporated with different PMAMPs at W/B = 0.28 shows similar compressive strength-developing behavior and meets the designed strength value.