01658567

Component

To meet the requirements of rapid construction, rapid-hardening controlled low strength material (CLSM) containing recycled fine aggregate from construction and demolition (C&D) waste was prepared with the sprayed concrete accelerator. Eleven mixtures were made with different accelerator-to-binder (A/B), water-to-solid (W/S) and binder-to-recycled fine aggregate (B/R) ratios. The workability (flowability and bleeding rate) of fresh mixture and the mechanical properties (early strength, long-term strength and dynamic elastic modulus) of hardened material were tested. The results show that adding 20~50% accelerator can reduce bleeding rate of CLSM by 48.8~84.6%, without significant effect on the flowability. Improved flowability of CLSM can be achieved by increasing the W/S or B/R ratio, with increased or reduced bleeding rate, respectively. The optimal for best early strength development is 40%, with the early hour strength (2~4h) hitting 0.41~0.79 MPa. When holding A/B ratio constant, the early strength of CLSM is affected by the amount of cementitious materials and the actual content of free water. A highly accurate predictive model for the long-term strength of CLSM was established through regression analysis, in which three control parameters are taken into consideration. In addition, there is a power function relationship between the compressive strength and the dynamic elastic modulus. Dynamic elastic modulus can thus serve as an index for evaluation of the mechanical properties of CLSM.

This paper was sponsored by TRB committee AFS80 Standing Committee on Stabilization of Geomaterials and Recycled Materials.

18-01398

English

4p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Admixtures; Brick; Fine aggregates; Flowable fill; Wastes

Construction and demolition waste material

Construction; Highways; Materials

Transportation Research Board Annual Meeting 2018 Paper #18-01398

TRIS, TRB, ATRI

Jan 8 2018 10:21AM