Application of green calcium sulphoaluminate cement to prepare foamed concrete for road embankment

Synthesis conditions and performance of alite-strontium calcium sulphoaluminate cement have been studied by introducing strontium calcium sulphoaluminate into Portland cement clinker. The effects of gypsum on compressive strength, hydration degree and structure of hardened alite-strontium calcium sulphoaluminate cement paste were studied in this paper. Composition and structure of the hardened cement paste were analyzed by XRD and SEM. Results show that appropriate content of gypsum could contribute to the hydration of alite-strontium calcium sulphoaluminate cement. When gypsum content is 9%, the compressive strengths for 1d, 3d and 28d curing age are 30.7MPa, 59.5MPa and 105.5MPa, and the corresponding hydration degree are 40.4%, 57.5% and 85.8%, respectively. The hydration products of alite-strontium calcium sulphoaluminate cement are mainly ettringite (AFt), Ca(OH)2, C-S-H gel. Large amount of AFt formed at early curing age provides a sound basis for early compressive strength, and a lot of C-S-H gel generated at later curing age increases the density of the hardened paste.

Download Full-text

Determination of Tricalcium Silicates Crystal Forms in Belite-Barium Calcium Sulphoaluminate Cement

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.541-542.204 ◽

2014 ◽

Vol 541-542 ◽

pp. 204-208

Author(s):

Yan Ting Zhao ◽

Xi Chen ◽

Ling Chao Lu ◽

Yong Bo Huang ◽

Jie Zhang

Keyword(s):

Cement Clinker ◽

X Ray Diffraction ◽

Crystal Forms ◽

Sulphoaluminate Cement ◽

Cement System ◽

Calcium Sulphoaluminate ◽

Diffraction Peaks ◽

Method Of Extraction ◽

Calcium Sulphoaluminate Cement

Chemical method of extraction was adopted in the study, and aqueous solution of potassium hydroxide and sucrose (KOSH) was used to obtain the clinker rich in silicate phases (alite and belite) in order to get the crystal forms of tricalcium silicates (C3S) in the belite-barium calcium sulphoaluminate cement clinker. The crystal forms of C3S were finally determined by XRD (X-ray diffraction) spectrums through its characteristic windows of the diffraction spectrums. Results shows that, C3S exists in the innovative cement system mainly in the form of M1; C2.75B1.25A3can completely dissolve in KOSH solution while its dissolution is inhibited in the cement system; after KOSH treatment, diffraction peaks of C4AF disappear totally and peaks of C3A has weakened to great extent; for the cement clinker, the clinker ground for 90min has the best extraction rate.

Download Full-text

Influences of Microelement on Microstructure and Mechanical Performance of Alite-Strontium Calcium Sulphoaluminate Cement

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.168-170.466 ◽

2010 ◽

Vol 168-170 ◽

pp. 466-471 ◽

Cited By ~ 2

Author(s):

Qiu Ying Li ◽

Ling Chao Lu ◽

Shou De Wang

Keyword(s):

Mechanical Performance ◽

Sintering Temperature ◽

Cementitious Material ◽

Cement Clinker ◽

Testing Conditions ◽

Sulphoaluminate Cement ◽

Portland Cement Clinker ◽

New Type ◽

Calcium Sulphoaluminate ◽

Calcium Sulphoaluminate Cement

Alite-strontium calcium sulphoaluminate cement, a new type of cementitious material, is synthesized by combining strontium calcium sulphoaluminate with minerals of Portland cement clinker. The influences of excessive SO3 and SrO on the microstructure and performances of this cement are studied by XRD, SEM-EDS and lithofacies. The results show that the optimal excessive mass fraction of SO3 and SrO are 50% and 80%. The compressive strength of the cement prepared under the testing conditions reaches to 32.8MPa, 66.8MPa and 126.4MPa at 1d, 3d and 28d curing ages, respectively. The additions of SO3 and SrO are benefit to improve the content of strontium calcium sulphoaluminate, and promote the formation of alite at low sintering temperature.

Download Full-text