6 
COLORADO EXPERIMENT STATION 
ANALYSIS OF ARKANSAS RIVER WATER, TAKEN AT ROCKY 
FORD 
Total solids per imperial gallon 156.4 grains. 
Analytical results. 
per cent. 
Combined 
Grs. Imp. C 
SiO,. 
.. 0.428 
Calcic sulfate 
’64.942 
SO3 . 
,. 48.299 
Magnesic sulfate 
27.994 
CO. 
.. 1.858 
' Potassic sulfate 
0.942 
Cl . 
.. 4.667 
Sodic sulfate 
32.449 
Na .,0 . 
.. 18.662 
Sodic chlorid 
12.044 
KoO . 
.. 0.326 
Sodic carbonate 
7.007 
CaO . 
.. 17.090 
Sodic silicate 
1.358 
MgO . 
.. 5 • 993 
Ignition 
6. 797 
Ignition . 
.. 4-346 
Sum. 
.. TOI .669 
Sum 
153-533 
Oxygen equiv. to Chlorin. 
. . I. 05 I 
Excess sodic oxid 
3.832 
T otal . 
..100.618 
Total 
157.365 
The ground waters of the Arkansas valley have essentially the same 
composition; they of course, vary in the amounts of mineral matter, total 
solids, held in solution. The two small samples of drain water sent with 
these tiles illustrate this very well, one of them carried 1252.6 grains, while 
the other carried less than one half as much, 542.3 grains in an imperial 
gallon. 
The salient featurers in the composition of the salts present in the 
ground waters of this section are the large amount of sulfates and the 
presence of carbonates. The amount of chlorine or the corresponding 
chlorids is not large and are probably subordinate agents in the alteration 
of the cement. 
Mr. R. Feret says*; “No cement or other hydraulic product has yet 
been found which presents absolute security against the decomposing action 
of sea water.” Further, “The most injurious compound of sea water is 
the acid of the dissolved sulfates.” Again the same writer says; “It is note¬ 
worthy, however, that chloride of magnesia is almost without action, while 
the sulfate of magnesia acts energetically upon cement. * * *” 
It has further been established by Candlot, Michaelis and Deval work¬ 
ing independently, that calcic sulfate unites with calcic aluminate forming a 
hydrated sulfo-aluminate which expands greatly on crystallizing and is 
soluble in water. 
It is assumed that magnesic sulfate acts upon the calcic hydrate set 
free by the setting of the tri-calcic silicate, forming calcic sulfate which is 
then capable of uniting with the calcic aluminate with bad results. 
The ground waters found in the lower portions of our irrigated sec¬ 
tions contain a niixture of the sulfates of soda, lime and magnesia, with 
which there is usually associated some carbonate. Some of these waters 
are essentially solutions of sodic sulfate with a little sodic carbonate; others 
especially drain waters con'^ain calcic and magnesic sulfates w’th some car¬ 
bonate, possibly sodic carbonate. 
*Taylor & Thompson Concrete Plam & Reinforced. P. 400. 
