Construction Materials

A case-control study was conducted to understand the risk factors associated with kala-azar in diseaseendemic areas of Bihar, India. A total of 134 kala-azar cases treated at the Rajendra Memorial Research Institute of Medical Sciences in Patna and 406 healthy controls selected randomly from the neighborhoods of cases in their native villages were included in the study. Univariate analysis showed that education, a history of other diseases in the previous year, a history of kala-azar in the family, type of walls in houses, presence of a granary inside houses, presence of vegetation around houses, bamboo trees near houses, and irregular spraying around houses with DDT were risk factors. Multivariate analysis showed that a history of other diseases in the previous year (odds ratio [OR] ‫ס‬ 3.6, P ‫ס‬ 0.002), a history of kala-azar in the family (OR ‫ס‬ 1.8, P ‫ס‬ 0.03), mud-plastered walls in houses, (OR ‫ס‬ 2.4, P ‫ס‬ 0.0001], a granary inside houses (OR ‫ס‬ 4.3, P ‫ס‬ 0.0001), presence of bamboo trees around houses (OR ‫ס‬ 2.3, P ‫ס‬ 0.001), and houses not sprayed with DDT in the past six months (OR ‫ס‬ 3.4, P ‫ס‬ 0.0001) were significant risk factors for kala-azar. These results will be useful in developing kala-azar control programs for identifying intervention strategies such as better housing, regular and proper insecticide spraying, and promoting health awareness to the community residing in diseaseendemic areas for reducing transmission and incidence of this disease.

Background This study evaluated the effects of a combination of three ergonomic measures designed to reduce the risk of low back complaints among gypsum bricklayers. The measures focused on optimizing working height and reducing carrying distances. Methods A within-subjects (N ¼ 10) controlled field study was used to compare the effects of working with the ergonomic measures with those of working with conventional working methods at the worksite during the course of a full working day. Productivity, work demands, and workload were assessed.

An experiment to investigate the potential of a laser-induced plasma method for determining concrete compressive strength was conducted by focusing a Nd:YAG laser on concrete samples with different degrees of compressive strength. This technique was developed in light of the role of the shock wave in the generation of a laser-induced plasma. It was found that the speed of the shock front depends on the hardness of the sample. It was also found that a positive relationship exists between the speed of the shock front and the ionization rate of the ablated atoms. Hence, the ratio of the intensity between the Ca(II) 396.8 nm and Ca(I) 422.6 nm emission lines detected from the laser-induced plasma can be used to examine the hardness of the material. In fact, it was observed that the ratio changes with respect to the change in the concrete compressive strength. The findings also show that the ratio increases with time after the cement is mixed with water.

The European Biocidal Products Directive 98/8/EC requires a risk assessment concerning possible effects of active ingredients on the environment. Biocides can be leached from treated materials exposed to outdoor use. These emissions have to be estimated and evaluated during the authorization procedure. Different immersion and irrigation tests were performed to investigate leaching of biocides from façade coatings. Several marketed formulations of textured coatings and paints spiked with a mixture of commonly used active ingredients (OIT, DCOIT, IPBC, carbendazim, isoproturon, diuron, terbutryn, and Irgarol 1051) were investigated. The emission process can be described by time-dependent functions that depend on the test conditions. The results of all test procedures confirm that leachability is related to water solubility and n-octanol-water partition coefficient of the active ingredients and that leaching of biocides from façade coatings is mainly a diffusion controlled process. Other factors like the composition of the product, availability and transport of water, concentration of active ingredients in the coatings, as well as UV-exposure of the coatings influence biocide emissions.

A case-control study was conducted to understand the risk factors associated with kala-azar in disease- endemic areas of Bihar, India. A total of 134 kala-azar cases treated at the Rajendra Memorial Research Institute of Medical Sciences in Patna and 406 healthy controls selected randomly from the neighborhoods of cases in their native villages were included in the study. Univariate analysis

Column experiments were performed to examine (a) the potential for leachate from construction and demolition (C&D) debris landfills to mobilize naturally-occurring iron and arsenic from soils underlying such facilities and (b) the ability of crushed limestone to remove these aqueous phase pollutants. In duplicate columns, water was added to a 30-cm layer of synthetic C&D debris, with the resulting leachate serially passed through a 30-cm soil layer containing iron and arsenic and a 30-cm crushed limestone layer. This experiment was conducted for two different soil types (one high in iron (10,400 mg/kg) and the second high in iron (5400 mg/kg) and arsenic (70 mg/kg)); also monitored were control columns for both soil types with water infiltration alone. Despite low iron concentrations in the simulated C&D debris leachate, elevated iron concentrations were observed when leachate passed through the soils; reductive dissolution was concluded to be the cause of iron mobilization. In the soil containing elevated arsenic, increased iron mobilization from the soil was accompanied by a similar but delayed arsenic mobilization. Since arsenic sorbs to oxidized iron soil minerals, reductive dissolution of these minerals results in arsenic mobilization. Crushed limestone significantly reduced iron (to values below the detection limit of 0.01 mg/L in most cases); however, arsenic was not removed to any significant extent.

Although domestic computer use is increasing, most efforts to reduce energy use through improved power management have focused on computers in the workplace. We studied 20 households to understand how people use power management strategies on their home computers. We saw computers in the home, particularly desktop computers, are left on much more than they are actively used suggesting opportunities for economic and energy savings. However, for most of our participants, the economic incentives were too minor to motivate them to turn off devices when not in use, especially given other frustrations such as long boot up times. We suggest research directions for home computer power management that could help users be more green without having to dramatically change their home computing habits.

Introduction Environmental Aspect Nowadays, every country in our earth is looking into one of the most popular topic which is “the sustainability development for a better future”. The sustainable construction concept was introduced due to the growing concern about the future of our planet. This is due to construction industry is a massive consumer of natural resources and on the other hand a huge waste producer (Cachim, 2009). On the other hand, the cost of raw materials is increased while the natural resources are keeps on reduction. Thus, waste materials become a potential alternative in the construction industry. This waste material, when properly processed, it will be effective as natural construction materials and readily meet the design specifications standard. (Mannan, Ganapathy, 2004). There are some kinds of study about concrete design to obtain the solutions in this construction industry. By implementing industrial waste such as recycled coarse aggregate (RCA) in concrete ...

Quantifying or, more generally, estimating the severity of the possible consequences of occupational accidents is a decisive step in any occupational risk assessment process. Because of the lack of historic information (accident data collection and recording are incipient and insufficient, particularly in construction) and the lack of practical tools in the construction industry, the estimation/quantification of occupational accident severity is a notably arbitrary process rather than a systematic and rigorous assessment.

Leaching tests, Fourier transform infrared spectroscopy (FTIR), extended X-ray absorption fine structure (EXAFS) spectroscopy, and thermodynamic modeling were performed to investigate arsenate [As(V)] immobilization mechanisms in iron hydroxide sludge stabilized with cement. The sludge from a groundwater remediation site in Tacoma, WA was mixed and immobilized with premixed cement to reach cement-to-sludge ratios of 2.5, 3.3, 5, 10, and 20 (wt premixed cement/wt dry sludge). The EXAFS analysis determined that As(V) formed bidentate mononuclear complexes on the iron hydroxide surface in the sludge. The adsorbed As(V) had a characteristic FTIR band at 830 cm -1 . Cement treatment converted the adsorbed As(V) to calcium arsenate precipitate with a FTIR peak at 860 cm -1 . The chemical forms of the As(V) were incorporated in an adsorption triple layer model (TLM) to describe the leaching behavior of As(V) in a pH range between 3 and 12. Cement treatment significantly reduced arsenic mobility because of the formation of the sparingly soluble calcium arsenate. ES021027G FIGURE 8. Model prediction and experimental results of As distribution in the treated sample (C/S ) 10). The experimental points are Ext TCLP results with 0.1 M Na2CO3. Carbonate was not present in the experimental systems and model calculations unless it is specified. (AsT ) 0.326 mM, FeT ) 5.25 mM, CaT ) 94 mM).

Hydrogen sulfide oxidation on sewer pipe surfaces was investigated in a pilot scale experimental setup. The experiments were aimed at replicating conditions in a gravity sewer located immediately downstream of a force main where sulfide related concrete corrosion and odor is often observed. During the experiments, hydrogen sulfide gas was injected intermittently into the headspace of partially filled concrete and plastic (PVC and HDPE) sewer pipes in concentrations of approximately 1,000 ppm(v). Between each injection, the hydrogen sulfide concentration was monitored while it decreased because of adsorption and subsequent oxidation on the pipe surfaces. The experiments showed that the rate of hydrogen sulfide oxidation was approximately two orders of magnitude faster on the concrete pipe surfaces than on the plastic pipe surfaces. Removal of the layer of reaction (corrosion) products from the concrete pipes was found to reduce the rate of hydrogen sulfide oxidation significantly. Ho...

Presently in India, about 960 million tonnes of solid waste is being generated annually as by-products during industrial, mining, municipal, agricultural and other processes. Of this 350 million tonnes are organic wastes from agricultural sources; 290 million tonnes are inorganic waste of industrial and mining sectors and 4.5 million tonnes are hazardous in nature. Advances in solid waste management resulted in alternative construction materials as a substitute to traditional materials like bricks, blocks, tiles, aggregates, ceramics, cement, lime, soil, timber and paint. To safeguard the environment, efforts are being made for recycling different wastes and utilise them in value added applications. In this paper, present status on generation and utilization of both non-hazardous and hazardous solid wastes in India, their recycling potentials and environmental implication are reported and discussed in details.

Effect of acid rain on leaching and hydraulic characteristics. Leaching of calcium and lead are significantly affected by initial pH of acid rain. Decreasing rate of hydraulic conductivity is lower in acid rain case. Presence of SO 4 2-in acid rain increased the leaching mass and rate of calcium.

Herbicides are still used to control weeds on hard surfaces, including municipal, private and industrial sites. Used under unfavourable conditions, especially when rain occurs shortly after application, herbicides may run off to surface waters. Such losses of herbicides from hard surfaces are estimated to be much higher than for herbicides used in arable fields. In this study, three kinds of hard surface were evaluated: asphalt, concrete surface and gravel (fine and coarse). Three herbicides were applied: glyphosate, diuron and diflufenican. Adsorption isotherms of diuron and diflufenican to the three surfaces were determined. At different times after treatment with the herbicides, rainfall was simulated by use of a rain-droplet spray nozzle, and the run-off was collected for analysis. After this run-off event, the materials were immersed in water to measure desorption which, together with the compound in the run-off, gave a measure of the dislodgable residues. The apolar herbicides diuron and especially diflufenican adsorbed strongly to asphalt. The polar herbicide glyphosate lost 75% in run-off from asphalt but was adsorbed strongly to soil and concrete pavement.

The rapid urbanisation of many cities in south and south-east Asia has increased the demand for bricks, which are typically supplied from brick kilns in peri-urban areas. We report visible foliar damage to mango, apricot and plum trees in the vicinity of traditional Bull's Trench brick kilns in Peshawar, Pakistan. Visible injury symptoms, hydrogen fluoride concentrations in air, and foliar fluoride concentrations were all greater in the vicinity of brick kilns than at more distant sites, indicating that fluoride emissions from brick kilns were the main cause of damage. Interviews with local farmers established the significant impact of this damage on their livelihoods. Since poorly regulated brick kilns are often found close to important peri-urban agricultural areas, we suggest that this may be a growing but unrecognised environmental problem in regions of Asia where emission control in brick kilns has not been improved.

Rammed earth is an accessible, sustainable and increasingly popular building material. Owing to a lack of research, current design standards for rammed earth have taken a conservative stance on material attributes like shear strength. Evaluating the shear strength of rammed earth is particularly important in seismic areas because of the material's high mass, low ductility and propensity to fail in shear. Shear test methods designed for other materials have typically been used in practice to determine the shear strength of rammed earth. In this research the design shear strength guidance available in current earth building standards was compared with experimental shear strength results for stabilised rammed earth. The triaxial (geotechnical) and triplet (masonry) tests were used to evaluate specimens reinforced with natural fibres: sisal and New Zealand flax. Both shear test methods showed that the shear strength capacity of cement-stabilised rammed earth was greater than the current guidance provided in the earth building standards. Recommendations were made to use the triaxial test to evaluate the shear strength of stabilised rammed earth and to allow the use of design shear strength equal to 7% of the compressive strength.

This study investigates the feasibility and effect of poly(lactic) acid (PLA) on bitumen modification. The chemical and physical properties were evaluated for the modified bitumen produced with varying percentages of PLA ranging from 3 to 9%. Several testings such as the nuclear magnetic resonance (NMR), Fourier Transform Infrared Spectroscopy (FTIR), Gel permeation chromatography (GPC), penetration, softening and ductility, and thermal storage stability were evaluated. The results show that chemical interaction exists between PLA and bitumen. The GPC analysis indicates high compatibility of the bitumen with the PLA modifier. Moreover, the results indicated that the addition of PLA increased the consistency of modified bitumen. The storage stability and segregation of phases were positively affected in the PLA modified bitumen. The PLA and base bitumen interact at physical and chemical levels which results in enhancement of performance of modified bitumen to produce a high-quality binding material for pavement construction.

The presence and deteriorating action of microbial biofilms on historic stone buildings have received considerable attention in the past few years. Among microorganisms, fungi are one of the most damaging groups. In the present work, antimicrobial surfaces were prepared using suspensions of Ca(OH) 2 particles, mixed with ZnO or TiO 2 nanoparticles. The antimicrobial surfaces were evaluated for their antifungal activity both in the dark and under simulated natural photoperiod cycles, using Penicillium oxalicum and Aspergillus niger as model organisms, and two limestone lithotypes commonly used in construction and as materials for the restoration of historic buildings. Both Ca(OH) 2 -ZnO and Ca(OH) 2 -TiO 2 materials displayed antifungal activity: ZnObased systems had the best antifungal properties, being effective both in the dark and under illumination. In contrast, TiO 2 -based coatings showed antifungal activity only under photoperiod conditions. Controls with coatings consisting of only Ca(OH) 2 were readily colonized by both fungi. The antifungal activity was monitored by direct observation with microscope, X-ray diffraction (XRD), and scanning electron microscopy (SEM), and was found to be different for the two lithotypes, suggesting that the mineral grain distribution and porosity played a role in the activity. XRD was used to investigate the formation of biominerals as indicator of the fungal attack of the limestone materials, while SEM illustrated the influence of porosity of both the limestone material and the coatings on the fungal penetration into the limestone. The coated nanosystems based on Ca(OH) 2 -50%ZnO and pure zincite nanoparticulate films have promising performance on low porosity limestone, showing good antifungal properties against P. oxalicum and A. niger under simulated photoperiod conditions.

The effects of respirable dust from three commercially produced calcium silicate insulation materials were examined in laboratory rats by long-term inhalation and injection techniques. These calcium silicate products have been used as replacements for asbestos in the insulation of the engine rooms of ships, and the particle size distribution of the dust clouds generated for the experimental study closely matched those found in ships during the installation of this type of material. One year of exposure to a dust cloud of 10 mg/m 3 of respirable dust had no discernible effect on the length of survival of treated animals compared to controls. No pulmonary lesions were found that appeared associated with the inhalation of calcium silicate per se, but one sample did contain significant amounts of quartz and this did produce a few small pulmonary nodules. While two small pulmonary neoplasms, one malignant and one benign, were found in dusted animals, neither was the cause of death, and the incidence was not significantly different from the control group where no tumors were found. One peritoneal mesothelioma was found in an animal from one of the inhalation groups, but this was considered to be a spontaneous tumor as none of over 100 animals injected intraperitoneally with 25 mg of calcium silicate developed these tumors. While the white blood cell count of dusted animals, compared to controls, was significantly raised in all treated groups at the end of the dusting period, these figures were within the published normal ranges for laboratory rats. It was concluded that the three tested calcium silicate products were harmless to the rats of this species at the doses tested.

This paper reports the results of an investigation on material recovery by stabilization/solidification of bottom ash coming from a municipal solid waste incineration plant. Stabilization/solidification was carried out to produce artificial aggregate in a rotary plate granulator by adding hydraulic binders based on cement, lime and coal fly ash. Different mixes were tested in which the bottom ash content ranged between 60% and 90%. To avoid undesirable swelling in hardened products, the ash was previously milled and then granulated at room temperature. The granules were tested to assess their suitability to be used as artificial aggregate through the measurement of the following properties: density, water absorption capacity, compressive strength and heavy metals release upon leaching. It was demonstrated that the granules can be classified as lightweight aggregate with mechanical strength strongly dependent on the type of binder. Concrete mixes were prepared with the granulated artificial aggregate and tested for in-service performance, proving to be suitable for the manufacture of standard concrete blocks in all the cases investigated.

In line with the development in the construction sector and continuous need for many of concrete structures that meet the need of continuous population increase in Iraq. It became necessary to think in concrete construction be more economical through the use of alternative raw materials in concrete production. Also it is help to rid of materials that cause environmental problems. The first objective of this paper is to produce concrete less expensive. Second, reduce pollution of the environment in terms of use a type of glass which cannot be recycled in other industries. This type of glass will be used as a raw material in the concrete production instead of cement or sand by specific rates. Research results were carrying a good indicator about compressive strength when using a glass powder instead of cement; especially when the glass was grinding at a more time. When the compensation ratio instead of cement was 20%, and using glass was grinding by 16 hour; the results was a good. They were (31.99, 44.9, 51.64) in age (7, 28, 56) respectively, compared with standard samples which were (22.4, 36.51, 43.2).

A model that combines plasticity and damage mechanics is developed to assess both multiaxial monotonic and cyclic behavior of concrete. The model adopts a bounding surface concept and combines plastic deformation with the deformation due to damage. Plastic strain components are calculated by using the plastic modulus that is a function of the distance from the current stress point to the bounding surface along the deviatoric stress direction S o. Similarly, damage growth rate is obtained by the hardening modulus, which is a function of the distance just defined. The hardening behavior of concrete is assumed herein to be controlled by both damage and plasticity, while the strain-softening regime is controlled by damage processes only. The simultaneous use of the plasticity surface and the damage surface, leads to a constitutive model that accounts for the essential features of concrete such as pressure sensitivity, shear compaction-dilatancy, stiffness degradation, and softening behavior.

Microbiologically induced deterioration (MID) causes corrosion of concrete by producing acids (including organic and inorganic acids) that degrade concrete components and thus compromise the integrity of sewer pipelines and other structures, creating significant problems worldwide. Understanding of the fundamental corrosion process and the causal agents will help us develop an appropriate strategy to minimize the costs in repairs. This review presents how microorganisms induce the deterioration of concrete, including the organisms involved and their colonization and succession on concrete, the microbial deterioration mechanism, the approaches of studying MID and safeguards against concrete biodeterioration. In addition, the uninvestigated research area of MID is also proposed.

This paper seeks to situate architecture between the ridiculous and the profound using pop art as a medium. Andy Warhol’s “piss paintings” also known as Oxidation paintings are the subject of study in this paper. A recent call to design a museum dedicated to the work of Warhol in New York envisioned the museum as a vital forum in which diverse audiences of artists, scholars, and the general public become galvanized through a ‘creative interaction’ with the art and life of Warhol. The controversial subject of Warhol’s work presented us with several critical inquiries and challenges as to what constitutes as creative public interaction? We critically examined the relationship between pop art, architecture, and the ability to confront ridiculous realities that engage the public in a profound yet controversial act. We present our proposal as an act of structured vandalism which is supported by architecturally yet humorous illustrations.

This paper addresses the detection and monitoring of the development of epilithic phototrophic biofilms on the granite fac¸ade of an institutional building in Santiago de Compostela (NW Spain), and reports a case study of preventive conservation. The results provide a basis for establishing criteria for the early detection of phototrophic colonization (greening) and for monitoring its development on granite buildings by the use of color changes recorded with a portable spectrophotometer and represented in the CIELAB color space. The results show that parameter b* (associated with changes of yellowness-blueness) provides the earliest indication of colonization and varies most over time, so that it is most important in determining the total color change. The limit of perception of the greening on a granite surface was also established in a psycho-physical experiment, as Db*: þ0.59 CIELAB units that correspond, in the present study, to 6.3 mg of biomass dry weight cm 72 and (8.43 + 0.24) 6 10 73 mg of extracted chlorophyll a cm 72 .

Background Prevalence of exposure related respiratory symptoms and decreases in lung function are unknown among quartz dust exposed construction workers. Methods In a cross-sectional study (n ¼ 1,335), the occurrence of respiratory symptoms, was recorded and spirometric lung function was measured. Results were associated with exposure data and presence of radiographic abnormalities and compared with a reference population.

Time and cost overruns on construction projects during the project life cycle continue to pose great challenges to developing countries. There are many factors that impede on successful completion of projects on time, budget, and quality. This study sought to investigate on the factors that significantly contributed to time and cost overruns on construction projects in Kenya, evaluate their relative ranking; and to quantify their impacts. The study was based on a questionnaire survey among persons drawn from contractors, consultants and other stakeholders in the construction industry. Significant variables from the survey, revealed various underlying factors example; Inaccurate estimates of project financing division between design and construction teams, contractor inabilities, improper project preparation, poor resource planning, and interpretation of requirements, works definition, timeliness, government bureaucracy, and risk allocation as having been significant contributors to time and cost overruns. These variables and underlying factors have potential of recurring in future projects, there is need to anticipate their occurrence, and to continually design appropriate strategies and mechanisms to overcome or minimize their potential impacts. Recommendations are given to assist the construction sector and other construction stakeholders on how effective project management could be done on future projects planning and implementation. Projects owners, managers and agencies in developing their project management strategies, can use the findings of this project as a reference.

The aim of the present research work is to investigate the possibility of adding steel slag, a by-product of the conversion of iron to steel process, in the raw meal for the production of Portland cement clinker. Two samples of raw meals were prepared, one with ordinary raw materials, as a reference sample ((PC) Ref ), and another with 10.5% steel slag ((PC) S/S ). Both raw meals were sintered at 1450 • C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the steel slag did not affect the mineralogical characteristics of the so produced Portland cement clinker. Furthermore, both clinkers were tested by determining the grindability, setting times, compressive strengths and soundness. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of the steel slag did not negatively affect the quality of the produced cement.

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Industrial activities in Iraq are associated with significant amounts of non-biodegradable solid waste, waste plastic being among the most prominent. This study involved 86 experiments and 254 tests to determine the efficiency of reusing waste plastic in the production of concrete. Thirty kilograms of waste plastic of fabriform shapes was used as a partial replacement for sand by 0%, 10%, 15%, and 20% with 800 kg of concrete mixtures. All of the concrete mixtures were tested at room temperature. These tests include performing slump, fresh density, dry density, compressive strength, flexural strength, and toughness indices. Seventy cubes were molded for compressive strength and dry density tests, and 54 prisms were cast for flexural strength and toughness indices tests. Curing ages of 3, 7, 14, and 28 days for the concrete mixtures were applied in this work. The results proved the arrest of the propagation of micro cracks by introducing waste plastic of fabriform shapes to concrete mixtures. This study insures that reusing waste plastic as a sand-substitution aggregate in concrete gives a good approach to reduce the cost of materials and solve some of the solid waste problems posed by plastics.

Project cost is one of the three main challenges for the construction manager, where the success of a project is judged by meeting the criteria of cost with budget, schedule on time, and quality as specified by the owner. Many projects experience extensive delays and thereby exceed initial time and cost estimate. Available information, good estimating practice and experienced personnel are some of the factors found to have considerable impact on estimation accuracy. The successful execution of construction projects and keeping them within estimated cost and prescribed schedules depend on a methodology that requires sound engineering judgment. So the research aim is to conduct research study and process of exploring the existing model related to above three types of estimate and their contribution to civil engineering cost management and control especially getting motivated with the verification and validation component of CRASP methodology. The objective of this paper or scope of this research in this paper is to conduct literature study and review towards exploring innovative techniques such as Artificial Intelligence Techniques or Expert System Techniques available and applicable to make decision making or decision support regarding construction cost management and control at three levels: (i) before the actual civil engineering project design begins (ii) after detailed design but before execution and (iii) during project execution KEYWORDS: Intelligent methods, project cost estimation and control, construction cost estimation, innovative methods in construction management

The concomitant recycling of waste and carbon dioxide emissions is the subject of developing technology designed to close the industrial process loop and facilitate the bulk-re-use of waste in, for example, construction. The present work discusses a treatment step that employs accelerated carbonation to convert gaseous carbon dioxide into solid calcium carbonate through a reaction with industrial thermal residues. Treatment by accelerated carbonation enabled a synthetic aggregate to be made from thermal residues and waste quarry fines. The aggregates produced had a bulk density below 1000 kg/m 3 and a high water absorption capacity. Aggregate crushing strengths were between 30% and 90% stronger than the proprietary lightweight expanded clay aggregate available in the UK. Cast concrete blocks containing the carbonated aggregate achieve compressive strengths of 24 MPa, making them suitable for use with concrete exposed to non-aggressive service environments. The energy intensive firing and sintering processes traditionally required to produce lightweight aggregates can now be augmented by a cold-bonding, low energy method that contributes to the reduction of green house gases to the atmosphere.

Recycling of secondary raw materials is a priority of waste handling in the countries of the European community. A potentially important secondary raw material is the product of the thermal transformation of cement-asbestos, produced by prolonged annealing at 1200-1300°C. The product is chemically comparable to a Mg-rich clinker. Previous work has assured the reliability of the transformation process. The current challenge is to find potential applications as secondary raw material. Recycling of thermally treated asbestos-containing material (named KRYÁAS) in traditional ceramics has already been studied with successful results.

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Carpenters and other construction workers who install drywall have high rates of strains and sprains to the low back and shoulder. Drywall is heavy and awkward to handle resulting in increased risk of injury. The purpose of this study was to evaluate several low-cost coupling tools that have the potential to reduce awkward postures in drywall installers. Five coupling tools were evaluated using the Lumbar Motion Monitor that measures trunk kinematics and predicts probability of low back disorder group membership risk (LBD risk). Workers answered surveys about their comfort while using each tool. The results indicate that use of the 2-person manual lift and the J-handle provide the best reduction in awkward postures, motions, low back sagittal moment, and LBD risk. The two-person manual lift appears to be the safest method of lifting and moving drywall, though using the two-person J-handle also significantly reduces injury risk. Given that carpenters are skeptical about using equipment that can get in the way or get lost, a practical recommendation is promotion of two-person manual lifting. For singleperson lifts, the Old Man tool is a viable option to decrease risk of MSDs.

The manufacture of prefabricated building materials containing binding products such as ettringite (6CaOÁAl 2 O 3 Á3SO 3 Á32H 2 O) and calcium silicate hydrate (CSH) can give, in addition to other well-defined industrial activities, the opportunity of using wastes and by-products as raw materials, thus contributing to further saving of natural resources and protection of the environment.