The Use of Lightweight Fines for the Internal Curing of Concrete

The Use of Lightweight Fines for the Internal Curing of Concrete
By George C. Hoff, P.E., DEng.
President, Hoff Consulting LLC

The benefits of using lightweight aggregates in concrete to help reduce cracking in slabs and bridge decks has been intuitively known for decades by the lightweight aggregate industry but the reasons as to why this occurred were not extensively examined and the benefits were not widely promoted. It was believed, and correctly so, that the lower modulus of the LWA and the improved transition zone around the LWA particles due to their generally vesicular surface, helped reduce stress concentrations between the paste and the aggregate and those reductions subsequently reduced the amount of early-age cracking in the concrete. In the 1980's, the production of high-strength concrete (HSC) became more common and, to accomplish it, came the use of higher cement contents, supplementary cementing materials such as silica fume, fly ash and blast furnace slag cement, and lower water-binder ratios as a result of the extensive use of superplastizers.

Click here to download the full article