Hydration, mechanical property and C-S-H structure of early-strength low-heat cement-based materials

•The hydration heat of early-strength low-heat Portland cement is evaluated.•The hydration degree of pastes and structure of calcium silicate hydrate is studied.•The early strength of ESLHP cement and Portland cement mortars is investigated. Utilization of low heat cement is an effective way to decrease the cracking risk in mass concrete. This paper investigates hydration, mechanical property and calcium silicate hydrate (C-S-H) structure of early-strength low-heat Portland (ESLHP) cement-based materials. Due to the low content of C3S and slow hydration rate of ESLHP cement at early age, the hydration heat of ESLHP paste is lower compared with that of Portland cement (PC) paste. C-S-H in ESLHP cement paste has a higher degree of polymerization than that in PC one at late age. Besides, ESLHP cement has desirable early strength. The mechanical property of ESLHP mortar at late age is superior to that of PC mortar. The compressive strength of mortars is positively correlated with the mean silicate chain length in C-S-H.