Engineering Information Compendex

This study focuses on the deformation behavior of structural lightweight aggregate concrete (SLWAC) beams subjected to short-term loading. The study considers eight beams with a reinforcement ratio that varied from 0.30 to 0.55%. The inverse analysis approach, previously proposed by the authors, is used for tension-stiffening modeling of the SLWAC in flexure. The modeling considers the shrinkage effect. To represent the tension-stiffening effect in SLWAC beams, the flexural model reported in the literature is modified. To check the adequacy of the proposed modeling technique, the deflections predicted by a commercial finite element software package are checked against the test results of several beams reported in the literature. The comparative analysis reveals the satisfactory accuracy of the proposed modeling approach because the errors of the deflection prediction are within the 5% interval. Deformation analysis is illustrated for a simply supported slab designed following ACI requirements.

A multi-channel cyclone is a new generation air treatment equipment that can remove fine stiff particles of up to 2 microns from air flow and reach the general effectiveness of 95%. The technological processes such as a combustion, products processing (drying, chemical compounds insertion) generate an aggressive conditions into polluted dusty gas flow. These processes change the physical, chemical and mechanical properties of fine particulate matter. The treatment plant and its working operation affects the emission of the compounds and their concentration, water content of the gas stream (humidity) and temperature of the gas. The aim of this research is the special conditions formation in the air cleaning equipment and it is a first part of experimental research of aggressive conditions into a multi-channel cyclone. The carried out research was aimed at establishing parameters of the gas-vapour flow in the cyclone under the increased humidity and temperature of the purified flow. The flow was treated under simulation conditions in the laboratory using autoclave device, at the gas flow temperature of 20–150 °C and gas flow humidity of 50–95 %. Under an average flow velocity of 8, 12 and 16 m/s in the cyclone's channel.

Municipal solid wastes incineration (MSWI) in modern waste-to-energy plants reduces the volume of MSW by up to 90%. Incineration process also produces two types of by-products – bottom ash (BA) and fly ash (FA). Municipal solid wastes incineration BA is rich in heavy metals and salts. The disposal of MSWI BA may cause serious environmental problems. The objective of this study is to assess fresh bottom ash chemical composition and heavy metals such as copper (Cu), lead (Pb) and zinc (Zn) leaching values. The chemical composition determination indicates that Cu (400–800 mg kg-1), Pb (680–1760 mg kg-1) and Zn (1330–2010 mg kg-1) are major heavy elements in MSWI bottom ash. The results showed that the concentrations of Cu were 0.1–2 mg kg-1, Pb – 0.2–12.2 mg kg-1, Zn – 0.4–5 mg kg-1. In order to reduce the leaching of heavy metals from bottom ash, they should be pre-treated. The most commonly used technologies are weathering, washing and metals separation.