Influence of different curing conditions and water to cement ratio on properties of self-compacting concretes

• Published in: Construction & building materials 2020-03, Vol.237, p.117570, Article 117570
• Main Authors: Nematollahzade, Morteza, Tajadini, Azim, Afshoon, Iman, Aslani, Farhad
• Format: Article
• Language: English
• Subjects: Curing condition; Durability; EDS; Self-compacting concrete; SEM; Water to cement ratio
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2019.117570

•The strength variation in different curing conditions is more evident in the high W/C.•With increasing the W/C, the amount of particles is not hydrated and the pores have reduced the strength.•The durability tests showed the best performance in plastic curing and out-air curing conditions.•The microstructure study was also performed with SEM and EDS analysis. Along with the water-to-cement ratio (W/C) as a key factor in the investigation of the properties of the concrete, the conditions and the time of curing also play a very important role on its performance. Therefore, in this research, the effect of different curing conditions such as water curing (wc), plastic curing (pc), out-air curing (oac), room-air curing (rac), wet burlap curing (wbc), out-air-curing compound (oacc) and room-air-curing compound (racc) has been investigated on the properties of self-compacting concrete (SCC) for three different W/C (0.35, 0.40 and 0.45). For this purpose, in addition to fresh concrete tests, compressive strength, splitting tensile strength, water absorption, capillary water absorption, electrical resistivity tests and scanning electron microscope (SEM) of surface morphology and energy-dispersive X-ray (EDS) analysis on the hardened concrete phase were investigated. The results showed that the compressive and splitting tensile strength test had the best outcome in conditions wc, pc, wbc, racc and rac, respectively, at all ages. However, strength at oacc and oac conditions behave differently by changing the W/C and ages. After 56 days, methods pc and wbc, which have the least amount of water absorption at different W/C. In this research, up to 24 h, the lower capillary water absorption test belongs to method pc, wbc, oacc, wc, racc, rac and oac, respectively. According to the results, by decreasing the W/C ratio, the amount of electrical resistance of samples increases and for high W/C ratio the influence of curing methods on this parameter is clearly. The microstructural observations confirm the results described above.