Influence of moisture content on the contact-hardening properties of calcium silicate hydrate by direct compression
Journal article, 2021

The purpose of this study is to investigate the influence of moisture content on the contact-hardening properties of calcium silicate hydrate. The materials with moisture content ranging from 0 to 76% were directly compressed at the pressure of 40 MPa for three minutes to produce solid compacts. Bulk density, mechanical strength and water-resistant property of the compacts were measured, and temperature evolution of the powders during compaction was evaluated. An obvious increase in bulk density of compacts but a slight decrease in compressive strength was found with moisture content increased up to approximately 25%, ascribed to the lubricant effect of water films on the surface of particles that facilitates the rearrangement and spillage of particles. Moisture could reduce the temperature evolution by reducing surface energy of the particles, and separate the interparticulate bonding. Consequently, for the material with moisture content higher than 25%, the bulk density of the compacts was almost constant, but the compressive strength decreased dramatically. Different tendency was observed in the flexural strength that the value increased with moisture content increased up to 11%, attributed to the consolidation of particles and formation of hydrogen bonding, and the water- resistant property of the compacts was also improved. Subsequent decrease in flexural strength was due to the disruption of hydrogen bonding.

Interparticulate bonding

Compaction

Moisture content

Mechanical properties

Calcium silicate hydrate

Author

Shuping Wang

Chongqing University

Xiaoqin Peng

Chongqing University

Luping Tang

Chalmers, Architecture and Civil Engineering, Building Technology

Guangxiang Ji

Chongqing University

Lu Zeng

Chongqing University

Construction and Building Materials

0950-0618 (ISSN)

Vol. 278 122374

Subject Categories

Materials Engineering

Materials Chemistry

DOI

10.1016/j.conbuildmat.2021.122374

More information

Latest update

2/9/2021 1