Hydraulic setting systems based on fly ash etc. - mixed with lime have required amts. determined by sample prepn. with pH and compressive strength measurement (HU 28.11.77)

摘要

Prodn. of high strength hydraulically setting systems having a permanent constant of volume, simultaneously eliminating all chemical reactions which could occur in the final product, includes intense mixing and homogenisation of binder(s) with the base components and water and subsequent hardening at ambient or elevated temp. The base materials used are mineral earth or industrial by-products which harden in the presence of lime, and which contain SiO2, Al2O3, silicates or aluminates, capable of reacting with lime. The granulometry of the base component is =100 mu produced during homogenisation. Slaked lime or Ca(OH)2 is added as binder at 5-33 wt.% (CaO) wrt the base component. Cement or binder may also be added at 6-15 wt.% subject to a max. of 5-33 wt.%. To determine the amt. of binder required, a series of samples are prepd. from the basic component mixed with various binder compsns. and the samples are hardened either 32h at 100 degrees C or 6h at 160 degrees C, the pH being measured before hardening using a 5% aq. dispersion and the compressive strength afterwards. The raw binder material prepd. as above is stored for mixing with water etc. at point of use, and hardened within 7 days at ambient temp. or 3-8h at 70-100 degrees C in steam. Used for prodn. of mass concrete, concrete blocks and elements and dry products having hydraulic properties. Products of improved strength (>60kg/cm2) are obtd.