Kamseu Elie, Lancellotti Isabella, Sglavo Vincenzo M, Modolo Luca, Leonelli Cristina
Department of Engineering "Enzo Ferrari", University of Modena and Reggio Emilia, Via P. Vivarelli 10, Modena 41125, Italy.
Local Materials Promotion Authority, Nkolbikok Yaoundé 2396, Cameroon.
Materials (Basel). 2016 May 24;9(6):410. doi: 10.3390/ma9060410.
Amorphous silica and alumina of metakaolin are used to adjust the bulk composition of black (BSS) and white (WSS) steel slag to prepare alkali-activated (AAS) mortars consolidated at room temperature. The mix-design also includes also the addition of semi-crystalline matrix of river sand to the metakaolin/steel powders. The results showed that high strength of the steel slag/metakaolin mortars can be achieved with the geopolymerization process which was particularly affected by the metallic iron present into the steel slag. The corrosion of the Fe particles was found to be responsible for porosity in the range between 0.1 and 10 µm. This class of porosity dominated (31 vol %) the pore network of B compared to W samples (16 vol %). However, W series remained with the higher cumulative pore volume (0.18 mL/g) compared to B series, with 0.12 mL/g. The maximum flexural strength was 6.89 and 8.51 MPa for the W and B series, respectively. The fracture surface ESEM observations of AAS showed large grains covered with the matrix assuming the good adhesion bonds between the gel-like geopolymer structure mixed with alkali activated steel slag and the residual unreacted portion. The correlation between the metallic iron/Fe oxides content, the pore network development, the strength and microstructure suggested the steel slag's significant action into the strengthening mechanism of consolidated products. These products also showed an interesting adsorption/desorption behavior that suggested their use as coating material to maintain the stability of the indoor relative humidity.
偏高岭土的无定形二氧化硅和氧化铝用于调整黑色（BSS）和白色（WSS）钢渣的整体成分，以制备在室温下固结的碱激发（AAS）砂浆。配合比设计还包括向偏高岭土/钢粉中添加河砂的半结晶基质。结果表明，通过地质聚合过程可以实现钢渣/偏高岭土砂浆的高强度，这尤其受到钢渣中存在的金属铁的影响。发现Fe颗粒的腐蚀是造成0.1至10μm范围内孔隙率的原因。与W样品（约16 vol％）相比，此类孔隙率在B的孔隙网络中占主导地位（约31 vol％）。然而，W系列的累积孔隙体积（0.18 mL / g）仍高于B系列，后者为0.12 mL / g。W系列和B系列的最大抗折强度分别为6.89和8.51 MPa。AAS的断口ESEM观察表明，大颗粒被基质覆盖，这表明与碱活化钢渣混合的凝胶状地质聚合物结构与残留的未反应部分之间具有良好的粘结力。金属铁/铁氧化物含量、孔隙网络发展、强度和微观结构之间的相关性表明，钢渣在固结产品的强化机制中具有重要作用。这些产品还表现出有趣的吸附/解吸行为，表明它们可用作涂层材料以保持室内相对湿度的稳定性。
