There are broadly two types of Pozzolan - reactive and non-reactive. Both carry out a common function in that a Pozzolan has a VERY small particle size, so it fills in the gaps between the sand and cement particles, reducing voids and thus making the overall concrete far harder and stronger. A non-reactive Pozzolan does … Continue reading What is a “Pozzolan”?
Firstly, don't worry. As long as you catch this fairly early you can resolve it. Curling or warping generally happens when one side of the concrete dries out quicker than the other. So for example if you have used our Worktop Premix Kit and have left the concrete uncovered in the first 18 hours then … Continue reading I’ve made my concrete and its warped or curled. Why has this happened?