State of water in calcium sulfoaluminate cement paste modified by hydroxyethyl methyl cellulose ether

This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye’elimite were selected. Properties of cement mortar in fresh and hardened states were investigated, including the fluidity, consistency and water-retention rate of fresh mortar and the compressive strength, flexural strength, tensile bond strength and dry shrinkage rate of hardened mortar. The porosity and pore size distribution were also analyzed by mercury intrusion porosimetry (MIP). Results show that HEMCs improve the fresh state properties and tensile bond strength of both types of CSA cement mortars. However, the compressive strength of CSA cement mortars is greatly decreased by the addition of HEMCs, and the flexural strength is decreased slightly. The MIP measurement shows that HEMCs increase the amount of micron-level pores and the porosity. The HEMCs with different MS/DS have different effects on the improvement of tensile bond strength in different CSA cement mortars. PAAm modification can improve the tensile bond strength of HEMC-modified CSA cement mortar.

Download Full-text

Investigation on the performance of hydroxyethyl methyl cellulose modified cement mortars with Portland cement-calcium sulfoaluminate cement binders

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.122721 ◽

2021 ◽

Vol 283 ◽

pp. 122721

Author(s):

Guofang Zhang ◽

Shunxiang Wang ◽

Dawei Qiu ◽

Bo Wang ◽

Xiaoyu Wu ◽

...

Keyword(s):

Portland Cement ◽

Methyl Cellulose ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

Cement Mortars

Download Full-text

Effect of hydroxypropyl-methyl cellulose ether on rheology of cement paste plasticized by polycarboxylate superplasticizer

Construction and Building Materials ◽

10.1016/j.conbuildmat.2017.11.010 ◽

2018 ◽

Vol 160 ◽

pp. 341-350 ◽

Cited By ~ 41

Author(s):

Baoguo Ma ◽

Yi Peng ◽

Hongbo Tan ◽

Shouwei Jian ◽

Zhenzhen Zhi ◽

...

Keyword(s):

Cement Paste ◽

Methyl Cellulose ◽

Cellulose Ether ◽

Hydroxypropyl Methyl Cellulose ◽

Polycarboxylate Superplasticizer

Download Full-text

Effect of Steel Slag on Shrinkage Characteristics of Calcium Sulfoaluminate Cement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1036.263 ◽

2021 ◽

Vol 1036 ◽

pp. 263-276

Author(s):

Hao Ran Huang ◽

Yi Shun Liao ◽

Siraj Ai Qunaynah ◽

Guo Xi Jiang ◽

Da Wei Guo ◽

...

Keyword(s):

Compressive Strength ◽

Relative Humidity ◽

Cement Paste ◽

Steel Slag ◽

Autogenous Shrinkage ◽

Drying Shrinkage ◽

Chemical Shrinkage ◽

Calcium Sulfoaluminate Cement ◽

Calcium Sulfoaluminate ◽

Slag Content

The effects of steel slag with 0, 10%, 20 % and 40% content on the chemical shrinkage, autogenous shrinkage, internal relative humidity, and drying shrinkage of calcium sulfoaluminate cement paste were studied. The results show that the compressive strength of calcium sulfoaluminate cement paste at an early stage decreases gradually when the content of steel slag increases. When the steel slag content is 0 and 10%, the compressive strength of hardened cement pastes gradually decreases at 90 and 180 days, but the samples with steel slag content of 20% and 40% maintain the compressive strength growth within 180 d. With the extension of curing period, the gap of compressive strength is gradually narrowed. The autogenous shrinkage decreases with the increase of steel slag content and has a good linear relationship with the relative humidity inside the paste. The proportion of autogenous shrinkage to chemical shrinkage is deficient, and most chemical shrinkage occurs in the form of the pore volume. Although the trends of drying shrinkage and autogenous are consistent, the former is more severe than the latter.

Download Full-text