New Technique for Producing Vacuum Concrete


In this work a new technique is used to produce vacuum dewatered concrete. In this technique perforated PVC pipes encased in cotton cloth are used to dewater concrete from inside of concrete volume, rather than from the surface, as is the case in the conventional vacuum dewatering method. These pipes are laid in position inside concrete forms, and a vacuum pump is connected to the dewatering pipes, which is operated after casting of fresh concrete to remove the excessive water from internal portion. Properties of vacuum dewatered concrete using the new technique are investigated by a series of tests such as compressiveand flexural strength tests. Based on test results, the new technique improves concrete strength and other mechanical properties particularly at early ages. The new dewatering technique is a good alternative to the conventional vacuum dewatering technique and can have a wider range of practical applications than the conventional method.