ST4 is utilized in a variety of home, agricultural, and industrial applications, including garage floors, shed bases, interior floor slabs, drain/channel bedding, and benching, and is acceptable as a wearing surface for mild foot traffic. At 28 days, assume a strength of 20 N/mm2. The material will not require reinforcement until it reaches a minimum age of 12 months. Concrete's strength increases as it ages, so the aforementioned time frame is only an estimate. If you want your concrete to have maximum strength when it's installed, wait until it has fully cured before walking on it. Otherwise, you may get less than its full potential strength. The strength of fresh concrete depends on how much water it has absorbed during mixing. Concrete that is too dry (not enough air entrained) will be weak; conversely, concrete that is too wet can be difficult or impossible to work. A good rule of thumb is to add about 10% more water than required, just to be sure. For example, if you need 2,000 psi (13.8 MPa) concrete, add another 0.5% to 1% water based on the size of the aggregate to ensure adequate flow and strength. As mentioned, the strength of fresh concrete increases over time as it cures, so it's important to give it enough time to cure before you use it.