The mechanical characteristics of steam-cured high strength concrete incorporating with lightweight aggregate

•Influences of lightweight aggregate on static/dynamic mechanical properties of steam-cured concrete were investigated.•The relationship between elastic modulus, damping ratio and compressive strength of steam-cured concrete incorporating lightweight aggregates were established.•The mechanisms responsible for mechanical characteristics of steam-cured concrete with lightweight aggregate were discussed. In order to mitigate the thermal damage of steam curing process at elevated temperature on microstructure of concrete and thus prepare high quality steam-cured concrete, the effects of type and absorbing-water rate of lightweight aggregate on static and dynamic mechanical properties of steam-cured concrete were investigated by serials experiments in present paper. The temperature evolution of different positions in steam-cured concrete without and with lightweight aggregate during steam curing period was also tested. Result indicates that, compared to control sample without lightweight aggregate, the compressive strength of steam-cured concrete with 30% ceramsite sand replacing the same volume river sand is slightly higher while the one of sample with 30% expanded clay ceramsite is lower at 28-day age. Under the same compressive strength level, the static/dynamic elastic modulus of steam-cured concrete with 30% lightweight aggregate is lower than that of control sample, and the damping ratio of steam-cured concrete with 30% ceramsite sand is higher. Incorporation of lightweight aggregate into concrete will result in a delay of temperature rise, which is very important for alleviating the thermal damage of steam-cured concrete caused by elevated temperature at early age and thus is favourable of improving the compressive strength.