THE EFFECT OF SBR ON THE STRENGTH OF CONCRETE

บทคัดย่อ

This research aimed at evaluating the effect of the SBR on the strength of concrete. For normal concrete which is made of cement, sand, stone and water, but sometimes some extra admixtures like SBR need to be added into concrete to change the characters of concrete. Whether the SBR would change the strength of concrete is a question need to be considered before using it. There are two common methods to use SBR with concrete, mixing concrete with SBR and coating concrete surface with SBR modified mortar. In this experiment, the first method was that SBR were added into concrete mix by weight of cement 5%, 10% and 20% separately, meanwhile, casted some normal concrete samples with the same water cement ratio. For the second one was making a coat with SBR modified mortar on the surfaces of each concrete sample and cast some samples with SBR modified mortar as well. After demold, put them into a curing room and checked their strength after 7 days and 28 days separately.

After checked the strength of these concrete samples, the results showed that the 7-day strength of SBR modified concrete sample was a little bit lower than that of normal concrete; but for the 28-day strength of SBR modified concrete was almost same as that of normal concrete.