The Heavy Compaction Test, also known as the Modified Proctor Test, determines the moisture–density relationship under significantly higher compactive effort. It is specifically designed for projects involving heavy structural loads, such as high-traffic highways and airfields.
As compactive effort increases, the Maximum Dry Density increases while the Optimum Moisture Content decreases. This is the core principle behind the Modified Proctor test. By using a heavier rammer and a greater drop height, we simulate the massive energy of modern heavy-vibratory rollers.
The resulting density is significantly higher than that achieved in the standard test, creating a subgrade that is virtually incompressible. This is vital for airport pavements and high-load industrial foundations, where even minor settlement could lead to catastrophic structural cracking.