Study On The Adaptability Between The Mineral Compositions Of Alite-sulphoaluminate Cement Clinkers And The Admixture

In this paper, industrial raw materials and pure chemical reagents are utilized to makealite-sulphoaluminate cement clinker, and the adaptability between alite-sulphoaluminatecement clinker with different content of C₃S,C₄A₃S and C₄AF and the admixtures of fly ashand blast furnace slag are investigated.The results indicate that: with the content of C3S increasing, the setting time of the cementdelayed obviously, and the compressive strength of the cement increased at each age. With theaddition of admixtures, the setting time of the cement delayed, and the compressive strength ofthe cement decreased at each age. With addition of fly ash admixture, the early compressivestrength of the cement decreased more, while the later compressive strength decreased less.With addition of slag admixture, both the early and the later compressive strength of the cementdecreased less. As a whole, when C3S content was lower in the cement, it showed badadaptability for the additions of fly ash and slag; while it showed good adaptability when thecontent of C3S is higher.With the content ofC₄A₃S increasing, the setting time obviously shortened, the earlycompressive strength of the cement obviously increased, and the later compressive strengthincreased a little. With the content of C₄A₃S increasing, if the content of C3S is lower, theearly compressive strength and the later compressive strength showed the trend of firstincreasing and then decreasing; if the content of C3S is high, the early compressive strengthincreased gradually and the later compressive strength first increased and then decreased.With the addition of admixtures, the setting time of the cement delayed, and the compressivestrength of the cement decreased at each age. With addition of fly ash, the early compressivestrength of the cement decreased more, while the later compressive strength decreased less.With addition of slag admixture, both the early compressive strength and the later compressivestrength of the cement decreased less. In the matter of general strength, the strength ofalite-sulphoaluminate cement, with the content ofC₄A₃S from10%to15%, is higher. In thematter of adaptability, with higher content ofC₄A₃S, the alite-sulphoaluminate cement clinkersshowed better adaptability for fly ash; with lower content ofC₄A₃S, the alite-sulphoaluminate cement clinkers showed better adaptability for slag.With the content of C₄AF increasing, the setting time of the cement obviously delayed, thecompressive strength of the cement decreased at each age. With the addition of admixtures, thesetting time of the cement delayed, and the compressive strength of the cement decreased ateach age. With the addition of fly ash, the early compressive strength of the cement decreasedmore, while the later compressive strength decreased less. With the addition of slag, both theearly and the later compressive strength decreased less. And the alite-sulphoaluminate cementclinkers with lower C₄AF content showed good adaptability for admixtures.