GB862703A - Improvements in concrete piles - Google Patents

Abstract

862,703. Concrete piles. RAYMOND INTERNATIONAL Inc. Nov. 16, 1959 [March 17, 1959], No. 38688/59. Class 68(2). A concrete preparatory shell for a cast-in-situ pile is formed by driving into the ground a casing 32 and a mandrel 31, both resting on a driving shoe 33. Wet concrete is then poured into the space between the casing and mandrel, the casing is removed and a tapered cylinder 36 is driven along the mandrel to expand the concrete into contact with the walls of the hole. The cylinder 36 has a gasket 38 which wipes the mandrel clean, so that it can be removed and immediately re-used. The cylinder 36 is removed after the concrete has set and the central hole is filled with concrete. In a modification (Fig. 6) the cylinder 36 is replaced by a parallel or slightly tapered cylinder 45 with a ring 46 attached thereto, which forces the concrete 43 radially outwards as the cylinder 45 is drawn down over the mandrel 40. The ring 46 remains in the bore when the cylinder 45 is removed. In a second modification (Fig. 10) a cylinder 64 with a ring 65 formed at its lower end is positioned around the mandrel before the concrete is poured, and expansion of the concrete is effected by raising the cylinder 64. One or more vibrators may be used with this modification. In a third modification the method is used to construct a composite pile which comprises an upper concrete section 81 and metal sections 82 and 83. The metal sections 82 and 83 are secured to a driving ring 86 which carries a casing 87 and a tapered cylinder 88. The assembly is driven by a stepped mandrel 85 acted on through a helmet 90. Concrete 81 is placed either before or after driving and is supported until it sets by a tapered cylinder 88 so that the mandrel 85 may be removed for further use.