Abstract: The invention relates to a hydraulic cement composition comprising, as a carbonation inhibitor of the cement composition, at least one compound of the formula (I):A--(Y.sub.n --H).sub.lwherein A is a polyamine residue containing 2-10 carbon atoms,Y is --C.sub.3 H.sub.6 --O--,l is a number equal to 1-8,n is a number equal to 1-4,the product of n.times.l is equal to 13-20,the active hydrogen(s) involved in the amino groups in the polyamine residue being partly or wholly substituted with the residue(s) of propylene oxide.

Abstract: This invention relates to a method of forming a solid foundation in soft ground or stratum by mixing chemical agent into the soft ground soil to solidify it. This ground reforming method comprises the steps of driving a casing into the soft stratum to be reformed so that the casing encloses a volume of earth, moving the enclosed soil out of the casing, mixing and kneading the chemical hardener with the removed soil, then returning the mixed and kneaded soil into the casing, and finally pulling the casing up. The columnar piles thus formed of consolidated soil provide a solid foundation in the soft soil stratum, either independently or in combination. The columnar piles built up according to the method of this invention have uniform and high dynamic strength.

Abstract: A method for constructing a tubular pile foundation in soft soil formations comprises agitating the soft soil to form an agitated region like a tube with single annular section or tubes with conjugated annular section at a time, injecting chemical hardener and mixing it with the soft soil to solidify the agitated region in situ into a tubular pile or conjugated tubular piles. By repeating the foregoing steps, the structural wall of piles is constructed to provide bearing capacity with the soft soil formations.

Abstract: A concrete breaker, in which in breaking a concrete structure, the inclination of the main chisel is maintained within a desired angle by a limit switch to prevent the chisel receiving bed and the ram from being damaged at least two mini-chisels disposed opposite the main chisel are slidably arranged and driving means for these chisels are encased in a machine frame provided with machine beds so that the machine body may be formed smaller and lighter in weight.

Abstract: An apparatus for forming reinforced concrete walls in a trench including a reinforcing cage, protruding reinforcing and sealing means for positioning the protruding reinforcing adjacent to the ends of the reinforcing cage and sealing the ends of a unit wall while allowing the protruding reinforcing to extend beyond a unit wall.

Abstract: A process for the production of reinforced concrete walls in trenches involving preparing a trench of at least unit length, placing a reinforcing cage in the trench, fixing further reinforcing so that it will extend past the end of the unit, placing means to prevent the concrete from completely covering the further reinforcing and pouring the concrete.