| Title |
Development and Basic Tests of Lightweight Aggregate made from Waste Concrete Powder and Spoil Surplus Earth for Concrete |
| Keywords |
Waste Concrete Powder ; Spoil Surplus Earth ; Lightweight Aggregate ; Density |
| Abstract |
The waste concrete powder discharged from construction work has annually increased. Therefore, efficient disposal countermeasure for the waste concrete powder is urgently required. The purpose of this study is to efficiently treat waste concrete powder and to evaluate the feasibility of lightweight aggregate made from waste concrete powder. Several types of lightweight aggregate using waste concrete powder are experimentally manufactured with various mass ratios of clay, and tested for density, water absorption. Clay was selected from spoil surplus earth, dried and then crushed to pass a sieve of 300 ㎛. Waste concrete powder and clay were mixed in ratios of waste concrete powder: clay = (4-21) : (79-96) (by weight). The mixture was pelletized to pellets with similar diameters of 10-15㎜. The pellets were dried at a temperature of 110℃, and then sintered at temperatures of 1250-1265℃ for 10-20min. Physical properties of lightweight concrete are also tested. As a result, an experimentally manufactured lightweight aggregate with a recommendable waste concrete powder content is similar or superior in physical properties to the commercial lightweight aggregate. Conclusion obtained are summarized as follows :1) The density of lightweight aggregate is ranged from 1.14 g/㎤ to 1.42 g/㎤.2) The water absorption of lightweight aggregate is ranged from 0.92% to 2.50%3) The compressive strength of lightweight concrete is ranged from 30.2 MPa to 41.2 MPa. 4) The unit weight of lightweight concrete is ranged from 1.77 t/㎤ to 1.89 t/㎤. |