Experimental Research on the Properties of Rock-Filled Concrete

Abstract

In order to comprehensively evaluate the properties of rock-filled concrete (RFC) with the strength of C15, lab experimental test and in-situ test are applied to explore the mechanical, hydraulic, ultrasonic characteristics of RFC in Hantang reservoir dam. Four types of defects within RFC are shown from the appearance of borehole cores specimens: (1) large sized voids existing in interfacial transition zone (ITZ) between self-compacting concrete (SCC) and rock block (RB); (2) bad cohesion in ITZ; (3) joints within rock block; (4) voids within SCC. For hydraulic aspects, the average porosity of RFC is 14.10%; the permeability rate of RFC ranges from 2.41 Lu to 10.41 Lu, with the average of 11.32 Lu, occasionally more than 25.52 Lu due to interconnected defects. For ultrasonic aspects, the ultrasonic velocity of RFC conforms to lognormal distribution, with the average of 2993.3 m/s and standard deviation of 650.5 m/s. For mechanical aspects, the average cubic compressive strength of RFC is 22.55 Mpa, with the standard deviation of 4.09 Mp. Thus the data shows a relatively great dispersion due to uneven distribution of some defects in RFC, which deteriorate the quality of RFC. Through the experimental investigation, it is shown that the quality of massive RFC in the Hantang dam is obviously non-homogeneous, mainly influenced by construction technology.

A Comprehensive Literature Review on the Elastic Modulus of Rock-filled Concrete

“…As depicted in Figure 2, SCC is produced on-site at a batching plant and transported to the designated area using concrete mixers. It is advisable to provide a curing period of 14 days for each RFC casting layer, with a recommended thickness range of 1.8-2.0 m. It is imperative to strictly adhere to the regulations outlined in the "Occupational Safety and Health Design Law for Water Resources and Hydropower Projects (GB 50706-2011)" as mandated by the Ministry of Water Resources of the People's Republic of China in 2012 during the dam-building process [23]. Various experiments have been undertaken, encompassing evaluations of HSCC in terms of its capacity to fill gaps between rocks, compressive strength, and permeability [24].…”

Study on the Influence of Specimen Size and Aggregate Size on the Compressive Strength of Rock-Filled Concrete

“…He et al [7] conducted compression creep and shrinkage tests on RFC and SCC, revealing that the creep and shrinkage strains of RFC were lower than those of SCC; additionally, they found that rock aggregates had a significant impact on the creep behavior of RFC. Wei et al [8] tested the mechanical properties of RFC specimens by coring the borehole of the dam, which showed that the average compressive strength of RFC was slightly greater than the SCC strength, but much less than the rock strength. Li et al [9] conducted uniaxial compression tests on 39 RFC cube cutting specimens; these cutting specimens were taken from a large volume test block cast in situ using the same material, process, and environment as the construction site.…”