Part 7 (1/2)
Water 966144 -------- 1000000
An average analysis of a Thames cement may be taken to be as follows:--
Silica 2354 per cent
Insoluble residue (sand, clay, etc) 040 ”
Alumina and ferric oxide 986 ”
Linesia 120 ”
Sulphuric anhydride 108 ”
Carbonic anhydride and water 134 ”
Alkalies and loss on analysis 050 ”
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The following figures give the analysis of a sample of cement expressed in terms of the complex compounds that are found:--
Sodium silicate (Na2SiO3) 343 per cent
Calcium sulphate (CaSO4) 245 ”
Dicalcium silicate (Ca2SiO4) 6189 ”
Dicalcium aluminate (Ca2Al2O5) 1214 ”
DicalciuO) 097 ”
Calcium oxide (CaO) 1422 ”
Loss on analysis, &c 055 ”
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Dr W Michaelis, the Gerave much consideration to this matter in 1906, and formed the opinion that the free li, combines with the sulphuric acid of the sea-water, which causes thein its destruction He proposed to neutralise this action by adding to the mortar materials rich in silica, such as trass, which would combine with the lime
Mr J M O'Hara, of the Southern Pacific Laboratory, San Francisco, Cal, made a series of tests with sets of pats 4 in diae on the circu the tensile strength, all of which were placed in water twenty-four hours afterAt first soth solution” of sea-water having a chemical analysis as follows:--
Sodiunesiunesium sulphate 09 ” ”
Calcium sulphate 06 ” ”
Water 856 ” ”
1000