| 摘要 |
<p>PURPOSE: To efficiently, easily obtain at low cost highly segregation-resistant concrete by using high-sphericity artificial aggregates easy in specific gravity control with fine powder as raw material obtained by crushing a concrete waste material followed by sieving. CONSTITUTION: A concrete waste material is crushed and sieved to dispense a granule fraction >=5mm in granular size as a coarse aggregate material and a second fraction 0.3-5mm in granular size as a fine aggregate material; a third granular fraction <=0.3mm in granular size generated during the above operation is recovered as fine particles. Subsequently, 100 pts.wt. of the fine particles is blended with about 50 pts.wt. or less of cement and 10-40 pts.wt. of water and the blend is granulated in nearly spherical fashion with a granulator followed by hardening to produce an artificial aggregate. Finally, a mixture comprising the artificial aggregate and the other coarse aggregate and fine aggregate, etc., cement and water are kneaded to produce the aimed concrete. By this method, the specific gravity difference between the aggregate and mortar can be made smaller; therefore objective low-segregative concrete can be obtained.</p> |
