AG Mechanics CDE Practice Exam

Which of the following increases the compression strength of concrete?

1. gravel

2. plasticizers

3. retarders

4. water reducers

The correct answer is: gravel

Gravel is the correct answer as it increases the compression strength of concrete. Gravel is a coarse aggregate that provides strength and durability to concrete by forming a solid matrix with the cement paste. It helps to distribute the applied loads more evenly throughout the concrete, enhancing its ability to withstand compressive forces. Plasticizers, retarders, and water reducers are additives used in concrete mixtures for different purposes but do not directly increase the compression strength of concrete like gravel does. Plasticizers are used to improve workability and reduce water content, retarders slow down the hydration process, and water reducers reduce the amount of water needed for the mix.