compatibility of ultra high performance concrete as repair material

(a) Concrete substrate under water for 24hours before placing the overlaymaterial(b) Composite samples right after placingUHPC; before covering them withplastic.(c) Wet cloths covering the concretesubstrateFigure 3.15 Composite splitting tensile specimen casting process(d) Composite specimen after demolding.3.6.2 Slant shear and pull off testsAll concrete substrates were submerged into water for at least 24 hours before mixingUHPC. Approximately, one hour before casting UHPC, the substrates were taken out ofthe water tank and placed back into the moulds. The moulds were covered by wet clothafter assembling, as shown in Figure 3.16. For the slant shear samples, UHPC was placedinto the moulds by filling from the deepest corner to the shallow one while for the pulloff test, UHPC was placed into the moulds by putting it in one corner and allowing it toflow into the mould. Vibration for 5-10 seconds was applied once UHPC was filling mostpart of the mould. After pouring the overlay material, the composite specimens werecovered by plastic sheets for three days before demoulding; except a small number ofslant-shear samples that were demoulded and tested at 2 days.61