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At conditions within the range of those typically applied for commercial drinking water applications, the impact of ultraviolet and hydrogen peroxide (UV/H2O2) advanced oxidation (AO) on the concentration, spectral characteristics, hydrophobicity, and biodegradability of natural organic matter (NOM) in a raw surface water and ultrafiltered surface water was studied. At an initial H2O2 dose of 20 mg L–1, UV/H2O2 mineralized less than 15% of the NOM in raw surface water at a fluence of 1500 mJ cm–2. Natural organic matter in ultrafiltered surface water was mineralized by at least 27% after about 1500 mJ cm–2. Partial oxidation of NOM led to ring opening of aromatic structures, cleavage of conjugated double bonded carbon structures, and reduction in the degree of aromatic substitution. The UV/H2O2 AO preferentially reacted with hydrophobic fractions of NOM leading to the formation of hydrophilic products. The treatment oxidized recalcitrant NOM into more readily biodegradable compounds with significant increases in formaldehyde and acetaldehyde concentrations. Depending on NOM properties for a given water, UV/H2O2 AO may cause partial oxidation of NOM leading to the formation of biodegradable compounds. The presence of these species may need to be addressed with a downstream process capable of improving biological stability.

In the present study, the potential of ZnCl2 activated coir pith carbon for adsorption of phenol from aqueous solution was investigated. Batch kinetics and isotherm studies were carried out to evaluate the effects of contact time, initial concentration, adsorbent dose, pH, and temperature. Adsorption kinetics was tested for first order, second order, and Bangham’s model and rate constants of kinetic models were evaluated. Equilibrium isotherms for the adsorption of phenol were analysed by Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherm models. The Langmuir adsorption capacity, Q0, was found to be 92.58 mg g–1 of the adsorbent. pH effect showed that physical adsorption might be involved in the adsorption process. Thermodynamic studies revealed that the adsorption of phenol by activated carbon was an endothermic process. The negative value of ΔG0 indicated the spontaneity of the adsorption process. Removal of phenol from synthetic wastewater was also tested. This study showed that ZnCl2 activated coir pith carbon could be used as an efficient adsorbent material for the removal of phenol from water.

In the present study, masonry creep was experimentally investigated. Creep tests were performed on masonry prisms, which were produced using standard fired clay brick and standard Type S mortar. A total of 11 sets of loaded and unloaded masonry specimens were tested under sustained load with three main parameters: stress level, masonry age at loading, and relative humidity. The unloaded prisms compensated for the effects of shrinkage. In this article, the ability of a number of rheological models reported in the literature are examined for their ability to predict masonry creep. Moreover, a new rheological model, one that considers the effect of stress level and masonry age at loading, is proposed. The system parameters of the proposed model were identified using the experimental data. The proposed model was then validated using masonry creep data that was reported by other researchers, but not used in model development. It is shown that the creep behaviour of masonry can be modelled with good accuracy using the proposed rheological model.

The optimization of the production of fired clay brick is essential for the sustainability of the clay brick industry. While there exist areas for improvement of these bricks’ properties when they are used in severe climates, concerns — including nonrenewable resource depletion, increasing energy costs, and waste management — have become increasingly important in Canadian and global industries. One strategy to address these concerns is to use waste additives as fluxing agents in bricks. Use of these additives can decrease the dependency of the industry on nonrenewable resources and can improve brick strength and durability. The effect nonrecycled waste glass additives have on fired brick durability and mechanical and transport properties was investigated in this study. The variables studied were waste glass particle size and percentage added by mass. Microstructure was investigated using mercury intrusion porosimetry to determine the effect on pore structure. The results yielded an optimal percentage addition of waste glass.

Performance of dry-cast concrete masonry products (DCCMPs), which are becoming the product of choice for many applications, has yet to be assessed in a comprehensive manner. This study was undertaken to investigate the effects of mix design and manufacturing parameters on the mechanical and transport properties, as well as the freeze–thaw (F/T) durabilities, of DCCMPs. The variables studied were water to cement ratio, mixing time, vibration time, and curing regime. Freeze–thaw durability was assessed in accordance with the American Society for Testing and Materials (ASTM) standard C1262 by exposing specimens to four conditions: water, 3% NaCl, 4% CaCl2, and 4% MgCl2 solutions. Results revealed that 3% NaCl exposure yielded the most mass loss due to scaling, whereas 4% MgCl2 exposure exhibited the least. Increase in either water content, vibration time, mixing time, or use of moist curing led to improvement in the mechanical properties, refinement of large pores in the range of 40 to 400 μm, reduction of total porosity, and enhancement of F/T durability of capstones. Ionic sorptivity yielded a strong statistical correlation with mass loss due to F/T action in the presence of 3% NaCl and 4% CaCl2.

Twelve reinforced masonry wall specimens with nominal dimensions of 2400 mm × 800 mm × 150 mm were tested under eccentric compressive loading with varying eccentricity to thickness ratios, e/t, and end eccentricity ratios, e1/e2. Pinned-pinned support conditions resulted in a slenderness ratio of 17.1 for all specimens. Test results showed that the variation of ultimate load, Pu, and effective modulus of rigidity values, EIeff, at failure depended on the type of failure mode, which was influenced by e/t and e1/e2ratios and their interaction. Comparing ultimate loads obtained by test against those calculated using the EIeffvalues from the Canadian standard CSA S304.1-04 and against the ones calculated using the EIeffvalues proposed herein indicates that, while the moment magnifier method used in the current Canadian design standard to account for secondary effects is effective, the standard underestimates EIeffvalues, especially in regions where compression-controlled failure tends to predominate and, thus, leads to a conservative design. However, the use of proposed EIeffvalues in combination with the moment magnifier method provides estimations of ultimate loads in reasonably good agreement with test results.

The results of lateral resistance tests of masonry walls and shaking table tests of a number of models of masonry buildings of various structural configurations, built with various materials in different construction systems, have been analyzed to find a correlation between the occurrence of different grades of damage to structural elements, characteristic limit states, and lateral displacement capacity. On the basis of correlation between acceptable level of damage and displacement capacity, it has been shown that the range of elastic force reduction factor values used to determine the design seismic loads for different masonry construction systems proposed by the recently adopted European standard Eurocode 8 EN-1998-1 for earthquake resistant design are adequate. By using the recommended design values, satisfactory performance of the masonry buildings that have been analyzed may be expected when subjected to design intensity earthquakes with respect to both the no-collapse and damage-limitation requirements.

Strengthening masonry columns by spraying them with glass fibre reinforced polymer (GFRP) was investigated experimentally. The study was aimed at assessing the strength and strain increases imparted by the technique under both concentric and eccentric axial loading. Plain and steel-reinforced columns were tested. Twenty-four columns were constructed from Type S mortar and straight and bullnose clay masonry units. The columns were 1 m high and either 290 mm × 290 mm or 390 mm × 390 mm in cross section. Two thicknesses of sprayed GFRP (SGFRP) were attempted, but it was found to be difficult to maintain uniform thickness. Nevertheless, with only minor increases in strength, large increases in strain capacity were achieved with both the plain and reinforced columns under concentric axial compression. Eccentric loading reduced the effect of the SGFRP laminate on the strength of masonry columns. Failure of SGFRP included both mode I and mode III fractures.

Given sufficient anchorage to the diaphragms, out-of-plane walls in unreinforced masonry (URM) buildings have been shown to crack above midheight and then rock as two rigid bodies. This study investigates the sensitivity of the rocking response to the type of ground motion and the quality of the wall construction. Shake table tests were conducted on four full-scale multi-wythe walls, all with a height to thickness (h/t) ratio of 12 but of varying construction quality and subjected to three different ground motions. All walls experienced cracking at less than one half of the 2005 National Building Code of Canada (NBCC) level for Vancouver, but exhibited a stable rocking behaviour without collapse beyond a ground motion 1.5 times the 2005 NBCC level.

In this paper, a numerical method is developed to calculate deformations and stresses of the body of dry gas holders under gas pressure. The deformations of the wall plates are decomposed into out-of-plane bending and in-plane deformation. The out-of-plane bending of the wall plates is described by the theory of orthotropic plates and the in-plane deformation by the biharmonic equation of flat plates under plane stress. The theories of beam columns and beams are employed to analyze the columns and corridors, respectively. By considering compatibility conditions between the members and boundary conditions, equations for the determination of deformations and stresses of dry gas holders under gas pressure are obtained. Both the proposed approach and the finite element method are used to investigate the deformations and stresses of the body of a dry gas holder under gas pressure. The results from the proposed method agree with those from the finite element method. Because far fewer unknowns are involved, the proposed method is computationally more efficient than both the finite element method and the series method developed from the theory of stiffened plates.Key words: numerical approach, body of dry gas holders, gas pressure.

This paper presents the results of a receiver operating characteristic (ROC) curve analysis of the effectiveness of construction planning efforts, based on samples of building projects in Australia and the United Kingdom. The results of the study provide an evaluation of the extent of the effort that must be invested in planning and control activities to achieve success in the performance of construction projects. The study also illustrates the potential application of ROC curve analysis in construction engineering and management research. Planning efforts in a sample of 52 building projects in Australia and 37 building projects in the United Kingdom were evaluated and compared. This study builds on work done in an earlier study in which the concept of optimal planning of construction projects was explored. The ROC curve analysis offers several advantages over the regression methodology employed in the previous optimal planning study. The graphical representation of the relationship between sensitivity and specificity over all possible diagnostic cutoff points provides an insight into the interactions of the variables that was not apparent in the original methodology.Key words: construction planning, project planning, project management, ROC curve analysis, Australia, United Kingdom.