Title: Compaction and Lightweight SFRC Mine Cribs

Author(s): Antonio Nanni, Charles L. Corbitt, and Michael K. Phang

Publication: Symposium Paper

Volume: 105

Issue:

Appears on pages(s): 351-366

Keywords: compacting; cribbing; fiber reinforced concretes; metal fibers; lightweight aggregate concretes; mines (excavations); roofs; supports; Structural Research

DOI: 10.14359/2902

Date: 12/1/1987

Abstract:
Use of steel fiber reinforced concrete (SFRC) in mine roof support systems as a substitute of traditional wood construction has proven successful. Further improvements of this technology could be obtained using SFRC crib-blocks either consolidated by compaction or having a lightweight matrix. Test results indicate that both compacted and lightweight SFRC crib-blocks behave similarly to conventional SFRC construction, as reported in the literature. Half-scale crib models have a load-bearing strength of approximately 50 percent, the 28-day ultimate compressive strength of quality control specimens. The proposed compaction method has the advantages of decreasing portland cement content, relaxing aggregate gradation requirements, and easing fabrication. On the other hand, the use of lightweight aggregates in the conventional construction procedure facilitates product hauling and handling without impairing structural integrity.