Some behaviours of saline soils mixed with Na2SO4 and NaCl during cooling

The solidoid crystallization of https://www.w3.org/1998/Math/MathML" display="inline"> Na 2 SO 4 ⋅ 10 H 2 O , ( C 1 ) , and NaCl ⋅ 2 H 2 O , ( C 2 ) , , will form during saline soil cooling which is the main reason producing salt heave, AH with a regression equation https://www.w3.org/1998/Math/MathML" display="inline"> λ H = B 0 + B 1 C 1 + B , , where https://www.w3.org/1998/Math/MathML" display="inline"> B 0 − B 2 are constants. A suitable content of NaCl mixed in salphate saline soil would limit salt heave,and the criti cal one might be https://www.w3.org/1998/Math/MathML" display="inline"> C 20 = 2 % where the level of salt heave could be the lowest one. The effect of NaCl content on salt heave could be expressed by ; https://www.w3.org/1998/Math/MathML" display="inline"> Δ H = B 0 ′ EXP ( B 1 ′ | C 2 − C 20 | b ) γ d H 2 ′ , where B 0 ' — B 2 ' are constants and γ u is dry unit weight.