Preparation And Experimental Research On High-performance Ultrafine Powder Admixture

Admixture is an indispensable component of high-performance cement-based materials, not only can improve the performance of cement-based materials, but also to enhance the industrial waste used of turning waste into treasure. Although the combination of the components in the concrete case of a good has enhanced role, most of the admixture is added to some extent, will reduce the performance of concrete, especially early performance, generally increases performance admixture dosage showed a significantly decreasing trend and lead to difficulties in the construction and engineering quality problems.For mineral admixture with fly ash, slag and silica fume, by particle size analysis, multi-element analysis, XRD and SEM detection methods, the average particle diameter measured by ash 18 ?m, the average particle size of slag is 15 ?m, the average particle size of silica fume is 7?m, the average particle diameter of the cement is less than 20 ?m. The main chemical compound involved in the hydration reaction admixture composition:Fly ash is SiO2 and Al2O3, slag is CaO and SiO2, silica fume is SiO2. According to their physical properties and chemical composition explores mineral admixtures volcanic ash effect, since the rigid, filling effect and micro-aggregate effect.For three mineral admixtures single doped test, the test results by setting time and strength to draw, as the dosage increases, the early strength of cementitious materials decreased, while the latter has increased; Cementitious material silica fume in reducing clotting time, early and late strength of cementitious materials were improving. On this basis, the orthogonal experiment measured fly ash, slag, silica fume complex ratio of the three best-doped erbium complex is:fly ash 5%, slag 13%, silica fume 7%. Its initial setting time was 150 min, the final setting time was 300 min,3 d compressive strength of 22.48 MPa,28 d compressive strength of 55.12 MPa. Admixture for mechanical grinding, added early strength L-H, sodium and triethanolamine, get three complex proportional mixed KJ-1, KJ-2, KJ-3 have a good effect. Hydration for admixture XRD detection,20 angle of 18° and 34° are CH corresponding diffraction peaks, the peak height indicates that the sample has a lot of hydration reaction occurs when 3 days, the late 28 d of C2S, C3S weak diffraction peaks, indicating that the hydration reaction has been very full, this hydration samples obtained by SEM morphology observation well proven.