Effects Of HPMC And CMC On The Performance Of Concrete

CMC and HPMC can be added to mortar to maintain moisture and thickening.As the dosage increases, the level of mortar will be reduced.CMC is an ionic cellulose ether that can react with the Ca (OH) 2 when added to the mortar.There is no obvious improvement in the water retention performance of CMC, and its dosage is relatively large.However, HPMC is a non-ionic cellulose ether with stable performance.Adding a small amount of addition to the mortar is only one tenth of the CMC, which can greatly reduce the layering degree of mortar and play a good role in the process of retaining water.

When CMC and HPMC are mixed with mortar, bubbles are introduced.In particular, when HPMC dose is very low, a large number of small bubbles are introduced.These bubbles can play ball in mortar and improve the performance of mortar.But the amount of air bubbles can reduce the wet mortar density, after the grout hardening, mud will form the internal pore, this will loose mortar internal structure, so the strength of the mortar will be greatly reduced.

HPMC is added to mortar, and the bending strength of mortar will decrease, but the compressive strength will be greater.The upward trend of compressive strength ratio curve shows that adding HPMC can improve the toughness of mortar.