NON-DESTRUCTIVE TESTING FOR CONCRETE WITH METAKAOLIN CURED AT LOW TEMPERATURE

摘要

The performance of concrete containing metakaolin (MK), using non-destructive testing, and subjected to low temperature curing of 5°C is investigated. Cement was partially replaced (by mass) with 0%, 5%, 10%, 15%, 20% and 30% MK. The water to binder ratio was maintained at 0.5 for all mixes. Concretes were subjected to water and air curing at 5°C. Ultrasonic pulse velocity measurements were conducted on the specimens. During the first day of hydration, the concrete strength is substantially reduced especially at high MK content. However, the incorporation of up to 20% MK causes an enhancement in ultrasonic pulse velocity beyond 7 days of curing. The optimum amount of MK was found at around 10%. The ultrasonic pulse velocity for water cured specimens was generally higher than those cured in air.