Rapid Repair of Bomb-Damaged Runways. Phase I. Preliminary Laboratory Investigation PDF Download

Author: P. S. Bussone
Publisher:
ISBN:
Category : Cement
Languages : en
Pages : 35

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Book Description
Three cements have been studied for possible use in the rapid repair of bomb-managed runways. These are: (a) lumnite (L), a high-alumina cement which was blended with portland cements type I, II, and III, regulated-set cement, and other concrete admixtures; (b) regulated-set cement (R), a halogenated calcium aluminate cement which was blended with gypsum additives in varying amounts from 0 to 12.5 percent and also mixed with an accelerator, sodium metasilicate (SMS); and (c) ordinary portland cement with various accelerators, Sigunit (S), sodium metasilicate (SMS), and sodium carbonate. Compressive strength of 2-in. cubes were determined at ages varying from 45 min to 28 days to establish strength development information. With some cements, neat slurry grout-type mixtures were made and tested in the same manner as the mortar mixtures. Water-cement ratios varied from 0.50 to 0.70 for the mortar mixtures and flow, when measured, was determined by the flow table method. With the neat slurry mixtures w/c ratios varied from 0.30 to 0.80, the efflux time being measured by the flow-cone method. The results indicate the following: (a) that many of the accelerators and so-called fast-setting cements do not develop 1-hour strengths sufficient for use in rapid repair of bomb-damaged runways; (b) two materials studied have yielded 1-hour compressive strengths in excess of 1000 psi. One is a cement, regulated-set, a proprietary product of the Portland Cement Association, and the second is an accelerator, known as sodium metasilicate, which has shown promise in both mixtures of ordinary portland and regulated-set cements.