Final answer:
The most effective method for controlling shrinkage cracking in concrete is to provide joints, which allow for controlled cracking in predetermined locations. Additionally, higher strength concrete can help reduce shrinkage cracking. Adding more water or cement is not effective and can even worsen the problem.
Step-by-step explanation:
The most effective method for controlling shrinkage cracking in concrete is to provide joints, also known as contraction joints. These joints allow for controlled cracking in predetermined locations, relieving the stress caused by the shrinkage of the concrete as it cures. By providing joints, the cracking is confined to these predetermined areas, preventing random and uncontrolled cracking throughout the concrete.
Higher strength concrete can also help reduce shrinkage cracking. When the concrete has a higher compressive strength, it is less likely to crack due to shrinkage. This is because the higher strength can better withstand the internal stress caused by the shrinkage, resulting in fewer cracks.
Adding more water or cement to the concrete mix is not an effective method for controlling shrinkage cracking. In fact, adding more water can increase the shrinkage and weaken the overall strength of the concrete. Similarly, adding more cement without adjusting the water-to-cement ratio can lead to a mix that is too dry and prone to cracking.