Cement Equivalence of Metakaolin for Workability, Cohesiveness, Strength and Sorptivity of Concrete

Materials

J.J. Chen¹  Q.H. Li¹  A.K.H. Kwan²  P.L. Ng³  L.G. Li⁴ 

[1] Department of Civil Engineering, Foshan University, Foshan 528000, China;Department of Civil Engineering, The University of Hong Kong, Hong Kong 999077, China;Faculty of Civil Engineering, Vilnius Gediminas Technical University, LT-10223 Vilnius, Lithuania;School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510000, China;

关键词: cement equivalent factor;    cohesiveness;    metakaolin;    sorptivity;    strength;    workability;   

DOI  :  10.3390/ma13071646

来源: DOAJ

【 摘 要 】

A series of concrete mixes with metakaolin (MK) content ranging from 0 to 30% and water/cementitious materials (W/CM) ratio varying from 0.30 to 0.50 were produced for performance testing. The results showed that adding MK up to 20% as ordinary Portland cement (OPC) replacement best improved the 28-day and 70-day cube strengths, whereas adding MK up to 30% as OPC replacement always increased the cohesiveness and decreased the sorptivity, but impaired the workability. Moreover, the cement equivalent factor (CEF), i.e. the equivalent mass of OPC per mass of MK added, for each performance attribute, including workability and cohesiveness, was evaluated. Whilst the actual CEF of MK was generally higher at a higher W/CM ratio and lower at a higher MK content, overall, the average CEFs were found to be 1.98, 2.17, 3.83, 1.93, 2.12, and 4.70 for slump, flow, cohesiveness, 28-day cube strength, 70-day cube strength, and sorptivity coefficient, respectively. These CEF values indicated that the MK is a highly effective cementitious material for improving the cohesiveness, strength, and durability. Moreover, it has been demonstrated that the CEFs for workability and cohesiveness are useful parameters in aiding the mix design of MK concrete.

【 授权许可】

Unknown