concrete paver molds

By 1897, Sears Roebuck was selling 50-gallon drums of imported Portland cement for $3.40 each. Although in 1898 cement manufacturers were using more than 90 different formulas, by 1900, basic testing — if not manufacturing methods — had become standardized. It wasn’t until 1793 that the technology took a big leap forward when John Smeaton … Read more