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The provisioning of a minimum standard level of settlement and the designing of camps are among the primary and essential rights and requirements of those subjected to disasters or conflicts. The presence of shelters is essential to resist diseases and protect against natural and non-natural hazards. It is also important to maintain the dignity of humans in the family and social frameworks in tough situations. The present study involved the emergency tent of the UN high commissioner for refugees (UNHCR), Q-shelter, tarpaulin-concrete shelters, recycled-paper pipes, rock-block buildings, safe units, pre-construction wooden building system, lightweight steel frame (LSF) building system, insulating concrete formwork (ICF) building system, and sliding structure system. This study investigates the possibility of using new construction management methods and technologies in Iran to establish temporary settlement sites after disasters from different perspectives, such as consistency with environmental conditions, passive defense, cost, execution speed, ease of facilities, construction technologies, and execution quality via the hierarchical analysis approach. According to the final scores of new temporary settlement establishment methods, Q-shelters were found to be the most consistent method with environmental conditions. Also, the highest passive defense score was obtained for the LSF building system. Also, the final weights of the decision criteria indicated that the highest effect was derived for execution speed at a coefficient of 0.203. Finally, obtaining a score of 0.156, the LSF building system was found as the best building system in the mass housing project based on the six criteria, followed by the sliding structure building system in the second rank. Moreover, the smallest score was obtained for the rock block system. [ABSTRACT FROM AUTHOR]

Increase in population and its daily increasing in our today society results in an increase in housing demand while traditional methods are not applicable. The project preparation and realization processes, based on theoretical and empirical studies, a creation of goods, services, and technologies, are the most important human activities. Selection of effective technological systems in construction is a complex multi-criteria decision-making task. Many decision-makers refuse innovations once faced with similar difficulties. Therefore, using modern materials and methods in this industry is necessary. Modern methods increase quality and construction speed in addition to decrease energy consumption and costs. One of the problems in the way of any project is selecting construction system compatible with the project needs and characteristics. In the present research, different concrete structures such as common reinforced concrete (RC) structure, prefabricated, Insulating Concrete Formwork (ICF), 3D Panel and Tunnel Concrete Formwork (TCF) for buildings with limited floors in Iran are studied and compared from the viewpoint of different criteria like cost, time, applicability and technical characteristics with industrialization approach. Therefore, some questionnaires filled out by construction industry experts in order to compare criteria and sub-criteria in addition to evaluation of optimized structural systems. Then, results of the questionnaires ranked by Analytic Hierarchy Process (AHP) and the most effective alternative selected. The AHP results show that 3D Panel system 36.5%, ICF 21.7%, TCF 19.03%, prefabricated system 13.3% and common RC system 9.3% are the most and the least efficient systems respectively. [ABSTRACT FROM AUTHOR]

Although some theories argued that investment decisions are irrelevant to financing decisions under the assumption of perfect market, investment decisions and capital structure seem interdependent in real-world circumstances. Further, the past literature also suggested a close relationship between internal cash flows and investment decisions, that is, investment–cash flow sensitivity (ICFS), but this issue has not been closely examined in the restaurant setting. Therefore, the current study first proposes to examine ICFS in the context of the restaurant industry. More importantly, this study also examines a moderating role of franchising to better explain ICFS, considering a major role of franchising in the restaurant industry, based on theories of pecking order, resource scarcity, and risk sharing. Findings of the current study deepens the understanding of ICFS via franchising, making meaningful contributions to not only to existing ICFS literature but also restaurant franchising literature. [ABSTRACT FROM AUTHOR]

A novel assembly FRP (fiber-reinforced polymer)-concrete hybrid beams/decks system is proposed and investigated in this paper. The performance of FRP shear key (SK) connector, FRP stay-in-place (SIP) form, and their combination for the FRP-concrete hybrid beams/decks is evaluated. The slip modulus and interfacial shear capacity of SK, SIP and their combination were investigated via push shear tests with thirteen specimens and four-point bending test with three FRP-concrete hybrid beams. Push-out test results showed that SK has the same shear capacity level and about ten times the slip modulus compared with steel bolt (SB). The cross section of SK is not a significant parameter because all of the shapes can enhance nearly full composite action between the FRP girder and concrete block. SIP can supply a strong initial natural bond with concrete and substantially save the form for concrete casting. This connection-form system combines the SB, SK and SIP as a structurally optimized design of shear connection and the permanent form. The beam test revealed that this connection system supplied full composite action till the failure of the FRP girder. Deflection of the FRP-concrete beam with the novel system can be predicted using equations based on the full-composite action assumption. [ABSTRACT FROM AUTHOR]

The use of “ductile seismic frames,” whose proper seismic behavior largely depends upon construction details and specific design rules, may do not always lead to effective seismic resistant structures, as dramatically denounced by the famous Chinese artist Ai Weiwei in his artwork Straight. The artwork (96 t of undulating metal bars that were salvaged from schools destroyed by the 2008 Sichuan, China earthquake, where over 5,000 students were killed) is a clear denounce against the corruption yielding to shoddy construction methods. The issue of safe constructions against natural hazards appears even more important in developing countries where, in most cases, building structures are realized by non-expert workers, or even by simple “people from the street,” who does not have any technical knowledge on construction techniques and seismic engineering. In this paper, a brief history from the first frame structures to the more efficient wall-based structures is provided within Earthquake Engineering perspectives. The superior structural properties of box-type wall structures with respect to conventional frame structures envisage a change of paradigm from actual “ductility-based” Earthquake Engineering (centered on frame structures) toward 100% safe buildings through a “strength-based” design exploiting the use of box-type wall-based structures.

Heat and humidity processes occurring in external wall of heated buildings depend mostly on external climate factors, i.e. air temperature and relative humidity, rainfall, sun radiation and conditions inside rooms. In three layer walls the face layer is specially endangered as humidity together with negative temperatures contribute to lowering its durability. Increased humidity content results in lowering insulating properties of materials which in turn leads to increasing heat consumption in a building during the heating period. In the article there are introduced results of simulations performed with WUFI ®PRO 5 software which aimed at analysing the face layer humidity changes caused by: exploitation conditions defined by 3rd and 4th class of room internal humidity, external climate influence, partition orientation. The calculation were performed for two different internal partitions drying from technological humidity during the initial five years of building exploitation. The partition in question is a three layer wall with pore ceramic 25 cm thick and elevation layer of clinker brick 12 cm thick. In the first variant insulation is mineral wool, in the second - styrofoam. For the particular layers of analysed partitions initial humidity content was assumed as resulting from technological conditions for building walls. The simulation let us state the technological humidity drying period of face layer, as well as humidity changes during the later period of exploitation resulting from climate influence. It was stated that elevation layer humidity condition is strictly associated with applied thermo-insulating material and partition orientation according geographic directions. [ABSTRACT FROM AUTHOR]

A feasibility study in which a pultruded fibre reinforced polymer (FRP) plank was used as stay-in-place (SIP) form serving as formwork during wet stage and as reinforcement during hardened stage is presented here. First, the strength and stiffness of the FRP plank serving as formwork for concrete casting under construction stage was verified by sand-filling test. Then shear tests were carried out to develop proper bond technique between FRP and concrete, so that they can perform as composite structural member. Thirdly, static tests on beams were conducted to evaluate the load-carrying capacity and failure modes of the proposed hybrid beam. The overall investigation showed the feasibility of using the FRP plank as a SIP formwork. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the inelastic behavior of a newly-developed type of self-insulating concrete masonry shear wall (SCMSW) under in-plane cyclic loading. The new masonry system was made from concrete blocks with special configurations to provide a stronger bond between units than ordinary concrete masonry units. A total of six fully-grouted SCMSWs were prepared with different heights (1.59 to 5.78 m) and different vertical steel configurations. The developed masonry walls were tested under in-plane cyclic loading and different constant axial load ratios. In addition, the relationship between the amount of axial loading, the amount of the flexural reinforcement and the wall aspect ratios and the nonlinear hysteretic response of the SCMSW was evaluated. The results showed that the lateral load capacity of SCMSW increases with the amount of applied axial load and the amount of vertical reinforcement. However, the lateral load capacity decreases as the wall aspect ratio increases. The existence of the boundary elements at the SCMSW ends increases the ductility and the lateral load capacity. Generally, the SCMSW exhibited predominantly flexural behavior. These results agreed with those reported in previous research for walls constructed with ordinary units. [ABSTRACT FROM AUTHOR]

Bridge deck construction using stay-in-place (SIP) fiber-reinforced polymer (FRP) structural forms has shown promise as an efficient, rapid, and low-waste alternative to conventional methods. Several studies have shown that the load capacity of this system is typically governed by punching shear strength, although no design-oriented equations have yet been developed to predict failure load or deflection at service. In this paper, two simple design equations are proposed for the ultimate load and stiffness of concrete deck slabs with SIP FRP forms, derived from the results of a comprehensive parametric study using a rigorous finite-difference computer model that is readily available. The equations were then validated by using experimental results from a database of 52 tests reported in the literature including FRP SIP forms of several shapes, sizes, surface treatments, spliced connections, boundary conditions, environmental exposures, and loading protocols. The equations showed an average predicted-to-experimental nominal strength of 87% with a standard deviation of 19%. When applying the design code member resistance factor of 0.75 consistent with shear failure of FRP-reinforced decks, a conservative strength was predicted for the entire database. Stiffness, on the other hand, was less accurately predicted; however, the model provided reliable and accurate indication of whether deflection limit is satisfied or not. [ABSTRACT FROM AUTHOR]

This article presents the structural evaluation of textile reinforced cement composite elements as formwork and reinforcement for concrete shells. Different shell geometries of 10 m span and a height between 2.5 and 5 m are examined. On one hand, the minimum thickness of the composite element functioning as formwork for these shells is determined when supported with a different number of supports and for different concrete sections. On the other hand, the minimum thickness of the composite functioning as reinforcement is calculated to withstand the occurring maximum bending moment. For shells with a 10 to 15 mm concrete section, a minimum composite formwork of 5–6 mm is needed to carry the load of the cast concrete, while the minimum composite reinforcement needed to withstand the maximum occurring bending moment equals 2–3 mm. Conclusively, this preliminary numerical study demonstrates the structural potential of textile reinforced cement composite stay-in-place formwork for concrete shells and indicates the dominance of the casting stage over the final stage. More specifically, local buckling of the formwork is the determining factor and should drive future work towards this issue. [ABSTRACT FROM AUTHOR]

Concrete is a random heterogeneous materials and its properties are affected by the spatial distribution of its constituents. In particular, insulating concrete, a material designed for reducing heat conduction, contains numerous voids within the material, and these voids strongly affect the physical properties of the material, such as thermal conductivity and strength. The thermal insulation property of the material is enhanced as the void ratio increases, while the strength of the material decreases as void ratio increases. In this study, the effect of anisotropic pores on the material properties of insulating concrete is investigated to overcome this contradiction. A concrete specimen with anisotropic artificial pores is utilized in order to examine the effect of anisotropic pores on the material properties. The spatial distribution of pores within the specimen is visualized using X-ray tomography (CT) and quantitatively characterized using probabilistic description methods. The thermal and mechanical properties of the specimens are also examined by means of experiments and numerical simulations. The results show that an appropriate arrangement of anisotropic pores for a specific direction can be utilized for the reduction of thermal conductivity by minimizing the loss of material strength, and it can be a promising approach for developing more advanced insulating material. [ABSTRACT FROM AUTHOR]

Metal deck forms are frequently used in the steel building and bridge industries as formwork for the wet concrete slab. Although the forms are often relied on for stability bracing during construction in buildings, conventional connection details between the forms and girder top flanges in the bridge industry possess an eccentricity that limits the bracing performance of the forms. A research study to assess and improve the bracing potential of permanent metal deck forms (PMDFs) used in bridge applications was conducted. Recommendations from the research study were implemented on two steel I-girder bridges located on the IH-610 north loop in Houston. The use of the PMDF bracing resulted in the elimination of 680 intermediate diaphragms from the bridges. Before the implementation project, laboratory buckling tests were conducted on a twin-girder system with members and bracing that were identical to those used in the implementation project. To the authors' knowledge, this project represents the first time thatmetal deck forms were relied on for stability bracing of steel I girders in the bridge industry. This paper documents laboratory testing, design, and construction of the two bridges in which PMDFs were used as construction bracing for the steel I girders in the bridge superstructure. Laboratory test results showed that the forming system, which was at the lower span limit of PMDF systems frequently used in steel bridge systems, could provide suitable bracing for the two implementation bridges. Using metal deck forms for bracing, the bridges were designed with no intermediate diaphragms/cross frames. A total of 680 intermediate diaphragms that would have been required in a bridge with conventional bracing were eliminated. The implementation of the research recommendations in the design of steel bridges can result in substantial improvements on the efficiency and economics of bracing systems for steel bridge superstructures. [ABSTRACT FROM AUTHOR]

More and more, people are looking to build and live in different ways. They want houses with a high standard of living and reasonable production and maintenance costs. However, they also want to build a way that does not adversely affect their quality of life. Currently, the using of modern methods of construction (MMC) expands consistently year on year. MMC include prefabricated products made in the factory and also new methods of building that are site-based and they are regarded as a means of achieving higher quality, reducing time spent onsite, increasing safety and overcoming skills shortages in the industry. Aim of this paper is to analyze and compare, trough case study, technical, cost and technological parameters of house built by modern method of construction (from insulating concrete formwork) and by traditional method (from brick system). The subject of case study is house modeled in two variants of insulating concrete formwork and a variant bricks and ceiling system. In conclusion, there is selected optimal method and system for house construction through multicriteria optimization. [ABSTRACT FROM AUTHOR]

A full-scale experimental test was conducted to analyze the composite behavior of insulated concrete sandwich wall panels (ICSWPs) subjected to wind pressure and suction. The experimental program was composed of three groups of ICSWP specimens, each with a different type of insulation and number of glass-fiber-reinforced polymer (GFRP) shear grids. The degree of composite action of each specimen was analyzed according to the load direction, type of the insulation, and number of GFRP shear grids by comparing the theoretical and experimental values. The failure modes of the ICSWPs were compared to investigate the effect of bonds according to the load direction and type of insulation. Bonds based on insulation absorptiveness were effective to result in the composite behavior of ICSWP under positive loading tests only, while bonds based on insulation surface roughness were effective under both positive and negative loading tests. Therefore, the composite behavior based on surface roughness can be applied to the calculation of the design strength of ICSWPs with continuous GFRP shear connectors. [ABSTRACT FROM AUTHOR]

The structural behaviors of foam-insulated concrete sandwich panels subjected to uniform pressure have been evaluated. This study showed that the interface conditions such as composite and non-composite had a significant effect on the response of foam-insulated concrete sandwich panels, indicating that the simulated shear tie resistance should indeed be incorporated in numerical analyses. Finite element models were developed to simulate the detailed shear resistance of connectors and the nonlinear behaviors of concrete, foam and rebar components. The models were then validated using data from static tests performed at the University of Missouri. The modeling approach used here was compatible with the American Concrete Institute (ACI) Code and existing design practices. The results of this study will therefore provide improved methodology for the analysis and design of foam-insulated sandwich panels under both static and blast loadings. [ABSTRACT FROM AUTHOR]

A robust analytical model for predicting full response and ultimate load of concrete bridge decks constructed with fiber-reinforced polymer (FRP) stay-in-place (SIP) structural forms is presented. It adopts the plate theory to establish surface deflections, while incorporating concrete nonlinearity in compression and cracking in tension, as well as the degree of bond between the FRP SIP form and the concrete. The model accounts for various boundary conditions at the edges of the deck in both directions, including both finite and infinite width in the direction of traffic, and either fixed or hinged conditions in the other direction, depending on the connection to the support girders. A punching shear failure criterion was incorporated to predict the ultimate load. The model was validated against a large experimental database, and reasonable agreement was observed. The average percent difference in ultimate loads was 5.5%. The model was then used in a parametric study to assess the FRP reinforcement ratio in terms of the FRP plate thickness, the width of the deck parallel to traffic, and the span of the deck, which is the girder spacing. It was shown that reducing the FRP reinforcement ratio from 10.7 to 2.7% results in about a 20% reduction in punching shear ultimate load. The ultimate loads obtained for decks with (width/span) aspect ratios of 2.73, 1.33, 0.87, and 0.55 were 100, 94, 83, and 73%, respectively, of the ultimate load of the real condition of infinite width. Finally, the punching shear load decreased by about 18% as the deck span-to-depth ratio increased from 10 to 16.5. [ABSTRACT FROM AUTHOR]

Self-compacting concrete (SCC) has become increasingly popular in recent years, particularly in constructing heavily reinforced concrete structures cast with a stay-in-place form (e.g., concrete-filled tubular columns) where the quality of concrete is difficult to control and/or examine. When used in fiber-reinforced polymer (FRP) tubes, the SCC is subjected to confinement from the FRP tube. While many studies have been conducted on confined normal concrete (NC), research on confined SCC has been very limited. The few existing studies on confined SCC (e.g., steel-confined SCC and FRP-confined SCC) have shown that the behavior of confined SCC may be different from that of confined NC of the same unconfined strength. Against this background, this paper presents the results of a series of axial compression tests conducted to gain a better understanding of the behavior of FRP-confined SCC. The test variables included the concrete strength as well as the type and thickness of the FRP jacket. Similar to FRP-confined NC, the present tests showed that the strength and ductility of SCC can also be significantly enhanced by FRP confinement, and its stress-strain curve also has a bilinear shape. A comparison between the test results and an accurate stress-strain model developed for FRP-confined NC is also presented. The comparison shows that the behavior of FRP-confined SCC is generally similar to that of FRP-confined NC, although the lateral expansion of the former appears to be a little larger. [ABSTRACT FROM AUTHOR]

This research is focused on the influence of stay-in-place (SIP) forms on the corrosion of reinforcement in concrete bridge decks. The laboratory study plan contained a total of 27 specimens--nine cells of three specimens each. The nine cell test conditions were with and without SIP forms, one and two cathode bars for each anode bar, and spacing distances between cathode and anode of 2, 3, and 4 in. (51, 76, and 102 mm). The specimens were maintained at a constant temperature and humidity throughout the 45-month chloride ponding cycles with testing periods between 0 to 14 months and 35 to 45 months. Corrosion testing during the two test periods included concrete resistivity, half-cell potential, corrosion rate, and macrocell currents with chloride concentrations and autopsies at 45 months. The effects of SIP forms on micro- and macrocell corrosion of reinforcement were investigated by statistically comparing the performance of specimens with and without SIP forms. It was determined that microcell corrosion was the principal corrosion mechanism. The presence of SIP forms showed a reduction in macrocell currents; however, it had no significant influence on the corrosion rate of steel reinforcement. [ABSTRACT FROM AUTHOR]

In this study, the restraining actions induced by stay-in-place metal forms to concrete bridge decks are examined. A comparison between the behaviour of a concrete deck section constructed with regular stay-in-place metal forms and that constructed on a flat-bed geometry where the corrugations in the stay-in-place forms are filled with extruded polystyrene foam is conducted. Data consisting of three-dimensional concrete deck strains, thermal gradient profiles through the deck thickness, deck deflection profiles and reinforcement strains were recorded through a long-term sensory system consisting of 340 sensors embedded within the deck since construction. Analysis of stresses developed in the concrete deck material indicates that using the foam material to fill the corrugations proved to be successful in reducing the concrete shrinkage stresses at early age and also in reducing the constraining effects of the stay-in-place forms on deck expansion and contraction within the monitoring period of about 1 year. [ABSTRACT FROM AUTHOR]

Highlights: [•] Critical parameters of FRP stay-in-place formwork were examined experimentally. [•] Ten bridge deck sections were constructed and tested at 1:2.75 scale. [•] The effect of concrete strength and deck aspect ratio were investigated. [•] A critical aspect ratio of >1.5 allows deck sections to simulate in-place capacity. [•] Using low strength concrete only marginally decreases FRP SIP form deck capacity. [Copyright &y& Elsevier]

Highlights: [•] An intermingled fractal units is presented to model porous microstructure and thermal properties. [•] Even non fractal structures can be effectively modelled with an intermingled fractal units. [•] Applying this model thermal conductivity values in line with experimental data has been obtained. [Copyright &y& Elsevier]

In order to reduce on-site building time, the construction industry shows an increasing interest in stay-in-place formwork with a reinforcement function after concrete hardening, such as CFRP formwork confinement for columns. The current combined systems however do not answer the demand of the building industry for a material system that is both lightweight and fire safe. High performance textile reinforced cement (TRC) composites can address this need. They can be particularly interesting for the shear reinforcement of concrete beams. This paper describes a preliminary analysis and feasibility study on structural stay-in-place formwork made of TRC. Comparative bending experiments demonstrate that a fully steel reinforced beamand an equivalent beam with shear reinforcement in TRC formwork show similar yielding behaviour, indicating that the TRC shear reinforcement system actually works. Moreover, the cracking moment of the concrete was more or less doubled, resulting in a much lower deflection in serviceability limit state than calculated. Digital image correlation measurements show that the latter is due to the crack bridging capacity of the external TRC shear reinforcement. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the effectiveness of the proposed prefabricated insulating panel for the thermal insulation of exterior walls. Findings reveal the advantages of the introduced panels including cost effectiveness, unaltered architectural façades, and highest inner surface temperature. Moreover, a correction factor was introduced to obtain the temperature difference between inner and exterior walls.

In this study, pultruded glass fiber reinforced polymer (GFRP) corrugated plates, connected together through pin-and-eye connections, were investigated as stay-in-place (SIP) forms for concrete decks. The SIP form completely replaced the bottom layer of reinforcement, whereas a top GFRP mesh was provided. Special attention was given in simulating the details of deck connection to supporting girders. Full-scale deck specimens, including a control deck with conventional steel reinforcement, were cast on concrete supports simulating a girder spacing of 1,780 mm. The 410-mm-wide supports had a rough surface finish along with protruding steel stirrups to simulate the flange of an AASHTO type III girder. An additional cantilevered specimen was tested to examine the feasibility of using SIP forms in deck overhangs at exterior girders. The study also investigated the effects of GFRP plate thickness and bond with concrete on performance. All specimens, except the cantilevered one that failed in flexure, had a punching shear failure while the GFRP pin-and-eye connections remained intact. The system demonstrated excellent performance, with safety factors ranging from 3.5 to 4.9, relative to the half-axle service load, including impact factor, of standard design trucks. Deflections at service were less than span/1,600. The system also displayed significant deformability associated with gradual loss of strength beyond punching shear, a major advantage over conventional decks. Adhesive bond improved stiffness but had little effect on strength. Constructability issues are also addressed along with the detailing particular to this system. [ABSTRACT FROM AUTHOR]

Abstract: Insulated Concrete Form (ICF) walls are widely used for a full range of building designs including residential, theaters, schools, and hospitals. ICF manufacturers cite several advantages compared to traditional building materials but builders are concerned by honeycombing that may occur during the pouring of the concrete, where gaps are left in the concrete. The development of gaps generally occurs between the foam and the surface of the concrete. Acoustic sounding, a traditional inspection technique to locate voids, would be unsuccessful due to the plastic foam. In this research study, Ground Penetrating Radar (GPR) was proved successful in detecting gaps that developed between the foam and the concrete, voids intentionally created in the concrete, and voids that developed during the pouring operation. Small voids (e.g., less than ¾in.) were difficult to detect but are not likely to cause any hazard to the structural integrity of buildings. The tests were performed at different stages of concrete curing using both the 1500MHz and the 2600MHz antennas. It is shown in this paper that the first void in the concrete was detected at day 7. However the best results were achieved at day 28 of curing. Data analysis has shown the success of the 1500MHz antenna, but also the limits of the 2600MHz antenna in the detection of buried voids in ICF structures. [Copyright &y& Elsevier]

Ground Penetrating Radar (GPR) is a non-destructive evaluation technique that has been successfully used in several transportation applications, such as subsurface exploration and condition assessment. The main objective of this research was to present the use of GPR as a quality assurance technique in construction projects. Two applications are presented in this paper: 1) measuring the thickness of concrete pavement; and 2) inspecting insulated concrete form (ICF) walls. A high resolution 1.6 MHz ground coupled antenna was used to perform grid scans and measure concrete thickness in several pavement projects and locate air voids and reinforcing bars in ICF walls. Results indicated that GPR is an efficient and reliable technique that can determine the thickness of concrete pavement with an accuracy of 3 mm (1/8 in.) and detect air voids as small as 38 mm (1.5 in.) in ICF walls. [ABSTRACT FROM AUTHOR]

Modern concrete bridge decks commonly consist of stay-in-place (SIP) precast panels seated on precast concrete beams and topped with cast-in-place (CIP) reinforced concrete. Such composite bridge decks have been experimentally tested by various researchers to assess structural performance. However, a failure theory that describes the failure mechanism and accurately predicts the corresponding load has not been previously derived. When monotonically increasing patch loads are applied, delamination occurs between the CIP concrete and SIP panels, with a compound shear-flexure mechanism resulting. An additive model of flexural yield line failure in the lower SIP precast prestressed panels and punching shear in the upper CIP-reinforced concrete portion of the deck system is derived. Analyses are compared to full-scale experimental results of a tandem wheel load straddling adjacent SIP panels and a trailing wheel load on a single panel. Alone, both yield line and punching-shear theories gave poor predictions of the observed failure load; however, the proposed compound shear-flexure failure mechanism load capacities are within 2% accuracy of the experimentally observed loads. Better estimation using the proposed theory of composite SIP-CIP deck system capacities will aid in improving the design efficiency of these systems. [ABSTRACT FROM AUTHOR]

Innovative, sustainable construction products are emerging in response to market demands. One potential product, insulating concrete forms (ICFs), offers possible advantages in energy and environmental performance when compared with traditional construction materials. Even though ICFs are in part derived from a petroleum-based product, the benefits in the use phase outweigh the impacts of the raw material extraction and manufacturing phase. This paper quantitatively measures ICFs' performance through a comparative life cycle assessment of wall sections comprised of ICF and traditional wood-frame. The life cycle stages included raw materials extraction and manufacturing, construction, use and end of life for a 2,450 square foot house in Pittsburgh, Pennsylvania. Results showed that even though building products such as ICFs are energy intensive to produce and thus have higher environmental impacts in the raw materials extraction and manufacturing phase, the use phase dominated in the life cycle. For the use phase, the home constructed of ICFs consumed 20 percent less energy when compared to a traditional wood-frame structure. The results of the impact assessment show that ICFs have higher impacts over wood homes in most impact categories. The high impacts arise from the raw materials extraction and manufacturing phase of ICFs. But there are a number of embedded unit processes such as disposal of solid waste and transport of natural gas that contribute to this high impact and identifying the top unit process and substance contributors to the impact category is not intuitive. Selecting different unit processes or impact assessment methods will yield dissimilar results and the tradeoffs associated with every building product should be considered after studying the entire life cycle in detail. [ABSTRACT FROM AUTHOR]

This study examined the effect of aggregate size and density on the shear and tensile bond characteristics of the coarse sand coated interface between stay-in-place fibre-reinforced polymer (FRP) formwork and concrete. Shear and tension tests were performed for five test variables according to aggregate size and density. Based on the test results, the appropriate size and distribution density of the aggregates is examined. In addition, based on the shear test results, the local shear bond stress-slip model for each of the test variables was derived through an optimization process. La présente étude a analysé l’effet de la dimension et de la densité des agrégats sur les caractéristiques de cisaillement et de tension de l’interface recouverte de sable grossier entre les cadres en PRF qui demeurent en place et le béton. Les essais de cisaillement et de tension ont été réalisés pour cinq variables selon la dimension et la densité des agrégats. Selon les résultats des essais, la dimension et la densité de distribution appropriées des agrégats sont examinées. De plus, selon les résultats des essais en cisaillement, le modèle de contrainte-glissement du lien de cisaillement local pour chaque variable des essais a été dérivé en utilisant un processus d’optimisation. [ABSTRACT FROM AUTHOR]

Abstract: The investigation of a structural fiber-reinforced-polymer (FRP) stay-in-place (SIP) form used to construct and reinforce a deck for a prototype military bridge system is discussed in this paper. For this application the deck is subjected to combined bending and compressive longitudinal axial load because it also serves as the top chord of the truss for the bridge system. In an experimental program, deck specimens were tested in several configurations. The results are compared to ACI 440 design guide equations, and capacity prediction techniques are proposed for limit states associated with flexural and flexural-shear under the combined loading. It was found that the ACI 440 equations accurately predicted the flexural and flexural-shear capacities under combined loads provided that eccentricity due to the combined loading was accounted for in the calculations. [Copyright &y& Elsevier]

Abstract: In the past, the study of neutron penumbral imaging technique often relied on linear reconstruction methods. Due to the linear approximation, the linear methods often caused the aberration in reconstruction results. Furthermore, because the smooth neutron background that influences the linear reconstruction result is difficult to estimate and remove, the linear reconstruction methods cannot work well either. In this paper, we propose a new nonlinear method based on classical molecular dynamics to improve the results. This paper discusses the principle of the new method and presents some of the reconstruction results, which are then compared with the results of Wiener method, one of the linear methods. [Copyright &y& Elsevier]