Miracle concrete: the great modern industry (1909)
Miracle Pressed Stone Co. · Miracle Pressed Stone Co. · leaf 122
i … Fig. 3. A platform like this is easily built and never in the way. At seven days, the hand-mixed concrete showed only 53per cent, of the strength of the machine-mixed concrete; at 28days, 77 per cent.; at six months, 84 per cent.; and at one year,87 per cent. This has never been disputed, and the…
