Valorization of Modified Starch in Mortars
J. L. Wolf and J. Pera
Appears on pages(s):
bleeding; compressive strength; flow; mortar; setting time; starch;
This research was aimed at the use of agroresources as admixtures for mortar and concrete. Thirteen modified starches from potato, wheat, corn and waxy corn were investigated. They were compared to methylhydroxyethylcellulose (MHEC) and Welan gum for the following properties: thicknening effect, water retention, setting time and 28-day compressive strength. The study was carried out on standard mortars and the starch dosage was either 0.75 % or 0.25 % of the total dry matter (sand + cement). The results obtained show that the recommended dosage is 0.25 %, which is still economic compared to MHEC and Welan gum. The best performances were obtained with waxy corn starches and, to a less extent, with potato starches. The latter performed well except for water retention.