Textile reinforced concrete (TRC) shells for strengthening and retrofitting of concrete elements: influence of admixtures

The mechanical behavior under impact loading of concrete elements strengthened with shells of textile reinforced concrete (TRC) was studied. The strengthening shells were made of either alkali-resistant glass or polyethylene (PE) fabrics that were impregnated with several cementitious matrices modified by common admixtures. Testing the strengthened elements for impact loading (strain rate from 0.4 to 1 s(-1)) at flexure showed that the TRC reinforced elements conferred improved load capacity and impulse absorption. For glass strengthened TRC elements, the extent of the improvement depended on admixture grain size, such that smaller grain sizes were associated with better performance. For PE strengthened TRC elements, no similar dependency was found. These results correlate well with the behavior of the standalone TRC shells and with the properties of the fabrics themselves. PE TRC strengthened elements were found, via impulse loading tests, to have load carrying capacities comparable to those of elements strengthened with glass TRC, but without matrix additives. These findings suggest that low cost, commercially available PE textile could be used in TRC applications.