Show ORGANIC MATTER IN SANDS material unsuitable for co concrete dorete to be investigated by bureau of public roads prepared by the th united states of agriculture sands unsuitable for concrete on account of the presence of 0 loam or other organic matter are to be investigated by the bureau of public roads of the united states department of agriculture and methods of treatment demised to make them safe for use until recent years it often happened concrete made of good cement and well graded and apparently good sand would disintegrate and become worthless in such cases the poor lias has been attributed to all the IK lif Terent ferent things hah h go to make a poor concrete A A few years ago laboratory workers discoN discovered ered the effect of organic mutter tiu itter in sand and devised a simple test te st to dek determine ermine its presence in harmful quantities the bureau now hopes to find fill methods of treatment so that such sands can be used samples of sand from nil all parts of the country are desired and anyone Is invited to send lit in a sample in which the presence of organic matter Is suspected addressed to the hureau bureau of public roads washington Ing tott D C |