A Study on Cement Made by Partially Replacing Cement Raw Materials with Municipal Solid Waste Ash
The use of Municipal Solid Waste incinerator bottom ash (MSWI) and Calcium Carbide Waste (CCW) as a part of cement raw material was investigated. The purpose was not only to dispose of the wastes, but also to alleviate some environmental problems, by reducing resources usage, CO 2 emissions and energy consumption in cement manufacturing. The replacement of MSWI and CCW in raw meal was 5 and 10 percent. Chemical composition and general characteristics, as well as setting times and compressive strength, of the MSWI cements and CCW cements were tested and compared with conventional cement. The chemical compositions of MSWI cements and CCW cements were similar to the control cement, except that the SiO 2 component in MSWI cements was higher than that in control cement but the CaO component was lower. Setting times of cement pastes were slightly different when MSWI and CCW were used as raw materials in cement. The longer setting times of these cement pastes than those of control cement is due to lower C 3 S and higher C 2 S levels than in CC. Compressive strength of CCW cement mortars was closed to that of the CC cement, whereas compressive strength of mortar produced from MSWI cements was rather smaller than the control cement mortar, especially at higher MSWI percentags.
Effects of petrochemical wastes incinerator ash powder instead of Portland cement on the properties of concrete
Petrochemical wastes incinerator ash is generated from industries in which the landfi ll is the last step for their flowing. This research was performed for waste management of ash and its possible large-scale utilization in making concrete. An experimental investigation carried out to evaluate the mechanical properties of concrete mixtures in which Portland cement type II was partially replaced with Petrochemical Complex IncineratorAsh Powder (PCIAP). The cement was replaced with various amounts of PCIAP, i.e. 5%, 10%, 15%, 20%, and 25%. Tests were performed on the properties of fresh concrete as well as hardened concrete. Compressive, splitting tensile and flexural strengths, and modulus of elasticity were determined in 7, 28, and 90 days. Test results indicated that by using PCIAP as partial replacement of cement, stabilization, solidi cation, and neutralization treatment processes for the industrial wastes management were carried out, and the testresults of the mixture M-2 (5% PCIAP) indicated that it can be used to make concrete which is lighter than normal concrete and heavier than structural lightweight aggregate concrete.
Mechanical behaviour and durability of high volume fly ash cementitious composites
The purpose of this research is to separate different morphological particles of ASTM class F fly ash, and study their effect on mechanical behaviour and durability of high volume cementitious mixtures. In this research wet separation of raw fly ash is carried out, which resulted in three layers of different morphological particles. The first layer of particles float, comprise of about 1-5% of fly ash, is identified as cenospheres or hollow spheres. The second layer of particles is measured to be 55-60% of raw fly ash and consisting of porous spherical and rounded particles rich in Si and Al. The third layer particles is measured to be about 35-40% of raw fly ash. High volume fly ash cementitious composites containing second or third layer particles are tested under compression and bending, highlighting a higher strength and ductility in comparison to cementitious ones containing raw fly ash particles. KEYWORDS. Cementitious matrix; Raw fly ash; Second layer particles; Third layer particles.