Use of Pb blast furnace slag as a partial substitute for fine aggregate in cement mortar

Abstract

The technical properties of cement mortars containing natural fine aggregate that is replaced by lead blast furnace slag at 25 and 35% level were assessed at fixed water-to-cement (W/C) ratio and at fixed flow table value. The leachabilities of some toxic elements from the cement mortars were also assessed to test the environmental suitability of the slag for use in preparation of cement mortar. At fixed W/C ratio, the strength of the mortar decreased with increase of the slag content. On the other hand, at fixed consistency, strength increased with increasing slag content in the mortar composition. The concentrations of some toxic elements in the leachates collected from the mortars containing slag were slightly higher than for the control mortar, but the concentrations in the leachates remained within the regulatory limits for recycling in construction applications. For most elements, leaching from a mortar containing 35% of slag was similar to that from a mortar containing 25% of slag. Therefore, 35% of natural sand can be beneficially replaced with Pb slag to produce cement mortar without affecting the mechanical and leaching properties studied in this work.

Pre-treatment of municipal solid waste incineration (MSWI) bottom ash for utilisation in cement mortar

“…The arguments those provided in our previous communications can be used to explain the results [7,37]. It is also necessary to mention that the leaching result obtained in this investigation are slightly different from the similar results obtained for MSWI fly ah samples [2].…”

Adverse Effects of Using Metallurgical Slags as Supplementary Cementitious Materials and Aggregate: A Review

“…It can be observed that the porosity tends to increase when LZS is used as an aggregate. According to the findings of Saikia et al [ 89 ], the porosity of 28 d hardened paste rises from 17.32% to 21.03%, and the water absorption rises from 8.29% to 8.75% when the LZS admixture increases from 0 to 35%. Regarding the mechanical properties, Figure 11 shows that the results vary from different researchers.…”

“…This is because the lead slag and zinc slag have a lower fineness modulus with more angular shapes. Saikia et al [ 89 ] discovered that substituting natural fine aggregate with LZS delayed the setting time of composite paste ( Figure 2 ), and the setting time grew as the LZS concentration increased. With lead and zinc slag doping of 35%, the initial setting time and final setting time were extended from 323 min and 405 min to 787 min and 992 min, respectively, with an average extension of 2.4 times.…”

“…Saca et al [ 99 ] replaced cement clinker with LZS and found that the hydration degree of the binder decreased when the admixture was increased from 30% to 50%. Saikia et al [ 89 ] attributed this to the presence of Pb and Zn-containing phases. When these phases dissolved at a high pH value, Pb and Zn formed some insoluble compounds, as well as a thin film to seal the clinker particles, which eventually inhibits the hydration of cement.…”

Utilization of Water-Cooled and Air-Cooled Slag Aggregate in Concrete: A Solution to the Secular Economy

“…Several studies investigated the possibility of using WCS and ACS to replace natural aggregate (sand and crushed dolomite). The studies showed that using the steel slag aggregate in concrete mainly enhance the physical and mechanical properties of concrete [58][59][60][61][62][63][64][65][66][67].…”