Effective Width of Floor Systems for Application in Seismic Analysis

Effective width coefficients for floor systems have been developed for use in the analysis of frames subjected to lateral seismic loads. The results cover a wide range of the governing nondimensional parameters, and are applicable to floor slabs with supporting beams as well as to flat slabs. The effective width coefficients were derived from a parametric study of typical interior panels of floor systems using elastic finite element analysis. An example of the application of the use of the results in seismic analysis of low-rise building frames is presented.National Science Foundation Grants ENV 77-07190 and PFR 80-0258

Removal of organobromine compounds from the pyrolysis oils of flame retarded plastics using zeolite catalysts

Two flame retarded plastics have been pyrolysed in the presence of two Zeolite catalysts to remove the organobromine compounds from the derived pyrolysis oil. The flame retarded plastics were, acrylonitrile – butadiene – styrene (ABS) that was flame retarded with tetrabromobisphenol A and high-impact-polystyrene (HIPS) that was flame retarded with decabromodiphenyl ether. The two catalysts investigated were Zeolite ZSM-5 and Y-Zeolite. Pyrolysis was carried out in a fixed bed reactor at a final pyrolysis temperature of 440 ºC. The pyrolysis gases were passed immediately to a fixed bed of the catalyst bed. It was found that the presence of Zeolite catalysts increased the amount of gaseous hydrocarbons produced during pyrolysis but decreased the amount of pyrolysis oil produced. In addition, significant quantities of coke were formed on the surface of the catalysts during pyrolysis. The Zeolite catalysts were found to reduce the formation of some valuable pyrolysis products such as styrene and cumene, but other products such as naphthalene were formed instead. The Zeolite catalysts, especially Y-Zeolite, were found to be very effective at removing volatile organobromine compounds. However, they were less effective at removing antimony bromide from the volatile pyrolysis products, although some antimony bromide was found on the surfaces of the spent catalysts

Analysis of products from the pyrolysis of plastics recovered from the commercial scale recycling of waste electrical and electronic equipment

Three plastic fractions from a commercial waste electrical and electronic equipment (WEEE) processing plant were collected and investigated for the possibility of recycling them by batch pyrolysis. The first plastic was from equipment containing cathode ray tubes (CRTs), the second plastic was from refrigeration equipment, and the third plastic was from mixed WEEE. Initially, the decomposition of each of the plastics was investigated using a TGA linked to a FT-ir spectrometer which showed that the CRT plastic decomposed to form aliphatic and aromatic compounds, the refrigerator plastic decomposed to form aldehydes, CO2, aromatic, and aliphatic compounds, and the mixed WEEE plastic decomposed to form aromatic and aliphatic compounds, CO2, and CO. Each plastic mixture was also pyrolysed in a batch reactor to determine the halogen and metal content of the pyrolysis products, additionally, characterisation of the pyrolysis oils was carried out by GC-MS and the pyrolysis gases by GC-FID and GC-TCD. It was found that the halogen content of the oils was relatively low but the halogen and metal content of the chars was high. The pyrolysis oils were found to contain valuable chemical products and the pyrolysis gases were mainly halogen free, making them suitable as a fuel

Processing waste printed circuit boards for material recovery

PURPOSE We have investigated the use of pyrolysis for the processing of waste printed circuit boards (PCBs). The aim was to make the process of separating the organic, metallic, and glass fibre fractions of PCBs much easier and therefore make recycling of each PCB fraction more viable. DESIGN / METHODOLOGY / APPROACH The PCBs were pyrolysed in a fixed bed reactor at 850°C. The organic fraction released by the boards was analysed by a variety of gas chromatography techniques. The residue that remained after pyrolysis was analysed by ICP-MS to determine the type of metals that were present. FINDINGS When PCBs were heated to 800°C in an oxygen free atmosphere, the organic fraction decomposed to form volatile oils and gases leaving behind the metal and glass fibre fraction of the boards. The pyrolysed boards were very friable and the different fractions (metal components, copper power boards, glass fibre, etc) could be easily separated. The recovered metals could then be recycled by traditional routes with particular emphasis being placed on the recovery and recycling of rare and precious metals. The organic oils and gases which are produced during pyrolysis of PCBs can either be used as a chemical feedstock or as a fuel. RESEARCH LIMITATIONS/IMPLICATIONS The research was only carried out on a very small scale so an investigation into scale-up must be performed. PRACTICAL IMPLICATIONS By using pyrolysis, the organic and metallic fraction of printed circuit boards can be separated and recycled. ORIGINALITY/VALUE This paper presents a novel method for resource recovery from PCBs

Quantification of polybrominated diphenylethers in oil produced by pyrolysis of flame retarded plastic

In recent years, there has been extensive research into using pyrolysis to convert toxic brominated plastics into safe, bromine free fuels. However, there has been little investigation of the polybrominated diphenyl ethers (PBDE) that are present in the pyrolysis oils. PBDEs are brominated flame retardants that are extremely toxic and are difficult to analyse owing to the existence of 209 different congeners. In this work, the authors have investigated the PBDEs present in the pyrolysis oil of high impact polystyrene which contained decabromodiphenyl ether as a flame retardant. The plastic was pyrolysed in a fluidised bed reactor and the resulting oil was subjected to a rigorous clean-up procedure to remove interfering compounds before the PBDEs were quantified using gas chromatography–mass spectrometry. It was found that the most prominent PBDEs in the oil were 3-monoBDE, 4-monoBDE, 3,49-diBDE, 3,39,4-triBDE and 2,29,4,49,5,69-hexaBDE. The lesser brominated PBDEs were more prevalent than the more heavily brominated PBDEs

Studies on the Seismic Design of Low-Rise Steel Buildings

The behavior of low-rise steel shear buildings, moment frame buildings, and X-braced buildings, subjected to earthquake base motion, is studied using inelastic time-history analysis. Two simpler methods of analysis, the modal method and the quasi-static building code approach, are evaluated for practical use in calculating. response quantities. The application of the results of these studies to the practical design of buildings is discussed.National Science Foundation Grant No. AEN 75-0845

The Commonality of Earthquake and Wind Analysis

Earthquakes and wind loadings constitute dynamic effects that often must be considered in the design of buildings and structures. The primary purpose of this research study was to investigate the common features of general dynamic analysis procedures employed for evaluating the effects of wind and earthquake excitation. Another major goal was to investigate and develop a basis for generating response spectra for wind loading, which in turn would permit the use of modal analysis techniques for wind analysis in a manner similar to that employed for earthquake engineering. In order to generate wind response spectra, the wind loading is divided into two parts, a mean load treated as a static component and a fluctuating load treated as a dynamic component. The spectral representation of the wind loading constitutes a simple procedure for estimating the forces associated with the dynamic component of the gusting wind. Several illustrative examples are presented demonstrating the commonality.National Science Foundation Grants ENV 75-08456 and ENV 77-0719

Pyrolysis of latex gloves in the presence of y-zeolite

In this study we have investigated the possibility of processing waste rubber gloves using pyrolysis. Y-zeolite catalyst was employed to upgrade the pyrolysis products to give higher yields of valuable aromatic compounds such as toluene and xylenes. The composition of the pyrolysis products was determined using GC-MS, GC-FID, GC-TCD, and FT-IR. It was found that when rubber gloves were pyrolysed in the absence of a catalyst, the pyrolysis oil consisted mainly of limonene and oligomers of polyisoprene. When Y-zeolite was added to the reaction system, the yields of toluene, xylene, methylbenzenes, ethylbenzenes, and naphthalenes increased dramatically. The Y-zeolite also catalysed the decomposition of limonene, which was absent from the catalytic pyrolysis products. The presence of the Yzeolite catalyst also increased the yield of hydrocarbon gases. The tests were carried out at both 380°C and 480°C and it was found that the higher reaction temperature led to increased yields of all the major compounds, both in the presence and absence of the Y-zeolite catalyst

Approximate Dynamic Response of Light Secondary Systems

John I. Parcel Fund

Resistance of Reinforced Concrete Structures Under High Intensity Loads

John I. Parcel Fund