The authors, in continuing their other studies (Magnesia-dolomite plaster and gypsum-dolomite plaster, “Journal of Salt Science, Japan”, 5, No. 6, 251-256 (1951) and 7, No. 2, 46-52 (1953)), reported in the present paper results of various tests of fire-proof wall plasters, which are composed from light burned sea-water-or magnesite-magnesia (80-60 parts), semi-calcined (up to 750°C) dolomite (20-40 parts), calcined or semihydrated gypsum (CaSO4·1/2H2O) (10-20 parts), serpentine powder from asbestos making plant (10-30 parts) or calcined and extraction residue of jarosite powder (10-30 parts), and large amount (150 parts by weight) of saw dust were mixed and kneaded with diluted (Bé. 22°) bittern solution from salt-making plant. Many samples (about 24) of various mixing proportions were tested on their hardened strengths of bending and compressive tests. Among them 12 samples were tested on their fire proofness as wall plasters by the authorized fire-proof testing method. The studies are now being further continued and the results will be reported in the next paper.
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