Passive Force-Deflection Curves for Controlled Low-Strength Material (CLSM) and Lightweight Cellular Concrete (LCC)

摘要

Contractors are increasingly requesting to use flowable fill (CLSM) or lightweight cellular concrete (LCC) to replace compacted granular backfill at bridge abutments because they can be placed more rapidly. In addition, LCC reduces the settlement of the underlying soils which is attractive to engineers. To evaluate the passive force-deflection curves for these materials, large-scale lab tests were performed with LCC and CLSM backfills in addition to a granular backfill for comparison. The response of the LCC was similar to that of the granular backfill with somewhat higher peak force developing at about 2.5% of the wall height. Although the stiffness was about twice as high as the granular backfill, the post-peak reduction was less than that for the granular fill. In contrast, the CLSM had a stiffness about 10 times higher than the granular fill and reached the peak value at a deflection equal to 1% of the wall height. The CLSM experienced a rapid decease in strength of about 60% after the peak strength was reached. The ductility of the LCC makes it a more suitable material for seismic loading with higher displacement demands.