METHOD OF INCREASING STRENGTH OF WATER-CONTAINING SOFT SOIL USING FLY ASH MODIFIED WITH SULFURIC ACID

摘要

PURPOSE:To increase effectively the strength of water-containing soft soil, by using, as a strength-increasing agent, fly ash modified with sulfuric acid, gypsum and Portland cement, allotting these materials into two additives, and prescribing the order of their addition, their proportions, and their particle sizes. CONSTITUTION:The strength-increasing additive 1[A]comprises two materials: fly ash (A1) modified with sulfuric acid and gypsum or insoluble anhydrous gypsum (A2). The strength increasing additive 2[B]comprises Portland cement. These additives are mixed and used to increase the strength of soft soil. If it is required to increase the deodorizing strength against the soft soil, a bivalent iron salt[C]is used as a third additive before adding additive B. The ratio of additive A to additive B is 50/50-25/75, while that of material A1 to material A2 is 70/30-20/80. The order of addition and mixing of materials A1 and A2 are arbitrary before additive B is added, but in practice, it is preferred to add and mix them at the same time in the form of a mixture.