PROBLEM TO BE SOLVED: To provide a water-retainable block having both of excellent water percolation properties and water retainability, and further having high pumping performance, and to provide its production method. SOLUTION: The concrete block comprises a water-retaining material composed of porous particulates, and has a water-retaining content of ≥0.15 g/cm 3 , a sucking height of ≥70% and the coefficient of water permeability of ≥0.01 cm/sec. Preferably, the water-retaining material is composed of porous particulates with the average particle diameter of 0.15 to 1.2 mm composed of papermaking sludge incineration ash, and the water-retaining block comprises the water-retaining material of 37.5 to 87.5 pts.mass to 100 pts.mass of cement. COPYRIGHT: (C)2007,JPO&INPIT

Water-retainable block and its production method

PROBLEM TO BE SOLVED: To provide a concrete composition which has good handleability and can be packaged, and whose quality is kept constant; and to provide a hardened concrete formed by adding water to the concrete composition and kneading them, the hardened concrete having lightweight properties and non-shrinkage properties and being applicable for civil engineering and construction structures having a middle-or-larger cross-sectional surface.SOLUTION: An aggregate contained in the concrete composition comprises at least a middle aggregate, wherein the middle aggregate is shown by a grading curve covered in a range surrounded with a grading curve showing a lower limit of a fine aggregate and a grading curve showing an upper limit of a coarse aggregate, among grading curves drawn in a graph where a first axis shows a dimension of a sieve and a second axis shows a weight percentage of a passed aggregate, which then shows the weight of an aggregate passed through the sieve to the weight of shifted aggregates. The concrete composition does not contain the coarse aggregate having a fineness modulus (FM) larger than the middle aggregate.

Concrete composition and hardened concrete

PROBLEM TO BE SOLVED: To provide a permeable solid material equipped with a strength and a permeability to be usable as a pavement material by effectively using coal ash discharged from a thermal power plant and reduce its manufacturing cost by improving its strength and reducing a construction time in paving. SOLUTION: Coal ash 100, cement 30-150, water 10-70, and a superplasticizer 0.3-1.5 pts.wt. as major components are mixed-kneaded and hardened. COPYRIGHT: (C)2003,JPO

Permeable solid material and method of manufacturing the same

PROBLEM TO BE SOLVED: To provide a material capable of being easily and rapidly executed to form porous concrete excellent in compressive strength, surface finishing, water permeability or the like for a footpath, a veranda or a rooftop part SOLUTION: A premixed material for porous concrete contains cement such as high-early-strength portland cement good in the strength development, a lightweight aggregate having particle sizes of 15 to 10 mm and a specific gravity in oven-dried condition of >=20 and, as necessary, silica sand and/or a mixing material

Marui Hiroshi

Papers

Premixed material and porous concrete using the same