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Different in situ and laboratory tests are commonly used to determine the nature of salts and to improve the comprehension of degradation mechanisms. Although laboratory tests are more accurate, in situ tests yield faster results and require a significantly lower budget. This study aimed at collecting data on nine case studies of buildings (26 sample's analysis) showing salt induced damage and assessing the potential of diagnosis techniques. Two in situ (test strips and a spectrophotometer-field kit) and three laboratory techniques [X-ray diffraction (XRD), X-ray fluorescence (XRF) and infrared spectroscopy (FTIR)] were carried out. The results showed the importance of collecting samples from different materials and locations. It is concluded that the combination of a thorough description of the areas affected by salt damage, a survey of the building's history, the consideration of its surrounding environmental conditions, and simple in situ tests is a useful and straightforward diagnostic tool. Although results of in situ tests agreed with the global results from the set of laboratory analyses, no single analytical method was considered sufficient to accurately identify all the damaging salts in a sample because each one showed intrinsic limitations. [ABSTRACT FROM AUTHOR]

An experimental program has been carried out to study the performance of partially grouted, nominally reinforced (PG-NR) concrete block structural walls under in-plane seismic loading on a shake table. Five reduced-scale structural walls were constructed and tested under scaled versions of the 1940 El Centro, California earthquake, using its N-S component record with a constant axial compression load that represented a single-story building. The test walls were grouped into three categories. Type I and III walls had reinforcement at the wall end cells only, with vertical reinforcement ratios of 0.07 and 0.12%, respectively, based on the gross cross-sectional area of the walls. Type II walls were similar to Type I walls, but with an additional reinforcement bar located midlength of the wall with a vertical reinforcement ratio of 0.10%, also based on the gross cross-sectional area of the wall. The experimental results were documented and discussed with respect to wall lateral load capacity, stiffness degradation, period shift, displacement ductility levels attained, and relevant seismic-force reduction factors. The test results showed that PG-NR masonry walls can comprise a ductile seismic force-resisting system. Subsequently, PG-NR masonry walls have the potential to bridge the gap between unreinforced and reinforced masonry systems. The use of PG-NR masonry also results in a reduced cost compared with traditional reinforced masonry systems used in seismic zones that are typically fully grouted within the plastic hinge zones and require higher reinforcement ratios. [ABSTRACT FROM AUTHOR]

This paper describes the full-scale experimental evaluation of the out-of-plane flexural response of fully grouted RC masonry walls subjected to uniform static pressure and to dynamic pressure resulting from an explosion. The investigation was performed as part of a larger effort to improve the design methodologies for reinforced masonry subjected to blast loading. The masonry walls were non-load-bearing and vertically spanning, which represents a significant amount of common construction in the United States. Both single-wythe and veneer wall sections were evaluated. Two types of concrete masonry units were used, i.e., conventional and A-block concrete masonry units. The results of the program provide a better understanding of the ultimate dynamic capacities and ductility of reinforced masonry walls-both single-wythe and veneer walls-which will ultimately help engineers produce designs that are safer and more economical. [ABSTRACT FROM AUTHOR]

Hemp concrete is a sustainable lightweight concrete that became popular in the field of building construction because of its thermal and environmental properties. However; available experimental data on its hygrothermal behavior are rather scarce in the literature. This paper describes the design of a large-scale experiment developed to investigate the hygrothermal behavior of hemp concrete cast around a timber frame through a spraying process; and then coated with lime-based plaster. The equipment is composed of two climatic chambers surrounding the tested wall. The experiment consists of maintaining the indoor climate at constant values and applying incremental steps of temperature; relative humidity or vapor pressure in the outdoor chamber. Temperature and relative humidity of the room air and on various depths inside the wall are continuously registered during the experiments and evaporation phenomena are observed. The influence of the plaster on the hygrothermal behavior of hemp concrete is investigated. Moreover; a comparison of experimental temperatures with numerical results obtained from a purely conductive thermal model is proposed. Comparing the model with the measured data gave satisfactory agreement. [ABSTRACT FROM AUTHOR]