Question

Which of the following is not a method to control plastic shrinkage?

1 - Use of a richer mix design
2 - Use of a wind break
3 - Use of fogging
4 - Use of wet burlap

Answer 1

Using a richer mix design is not a direct method to control plastic shrinkage in concrete. To effectively control plastic shrinkage, maintaining moisture content and temperature during curing with methods like wind breaks, fogging, or wet burlap is essential.

Step-by-step explanation:

Among the options provided for controlling plastic shrinkage in concrete, using a richer mix design (option 1) does not directly prevent plastic shrinkage. While a richer mix can potentially yield a stronger final product, it doesn't specifically address the issue of plastic shrinkage, which occurs as concrete dries and hardens. To control plastic shrinkage, measures that maintain the moisture content and temperature of the concrete surface during curing are preferred. Such measures include the use of wind breaks (option 2) to reduce air movement over the surface, fogging (option 3) to maintain humidity, and covering with wet burlap (option 4) to keep the surface moist.