What is the role of hydroxypropyl methylcellulose in foam concrete

The reduced height of the test block in the mold after molding characterizes the effect of hydroxypropyl methylcellulose on the volume stability of foamed concrete. It can be seen that the dosage of 0.05% hydroxypropyl methylcellulose is the ideal dosage, and when the dosage of hydroxypropylmethylcellulose is 0.05%, the reduction height is progressively increased. The analysis shows that when the hydroxypropyl methylcellulose is appropriate, it can reduce the volume shrinkage of the hardened body while improving the fluidity of the slurry. During the hardening process of the slurry, water is continuously lost. The internal foam is also constantly disillusioned, and the shortening of the hardened body is inevitable. This causes the volume of the hardened body to be unstable, and the mixing of hydroxypropyl methylcellulose not only supplies the hardened body It not only has a good water retention effect, but also stabilizes and hardens the first foam through the characteristics of slurry hardening and hydroxypropyl methylcellulose film hardening at the same time, so as to play a good foam stabilizing effect and reduce the shrinkage of hardened body volume.

Auxiliary foam stabilization

As the amount of hydroxypropyl methylcellulose was increased to 0.5%, the slump decreased slightly. The data show that when the hydroxypropyl methylcellulose content does not exceed 0.05%, the addition of hydroxypropyl methylcellulose can significantly improve the fluidity and viscosity of the foamed concrete slurry. After the hydroxypropyl methylcellulose is dissolved, a moist flexible elastic film is formed between the solid phase particles and the gas phase bubbles, which has an excellent smooth effect during the mixing process. Slurry is free and uniform “ball”, which effectively improves the fluidity of the freshly mixed slurry: but if the amount of hydroxypropyl methylcellulose exceeds 0.5%, the slurry will become too viscous and the fluidity will be greatly reduced. However, 0.05% hydroxypropyl methylcellulose not only ensures the slump, but also stabilizes the air bubbles, which is ideal for adding people.