Use of Residential Construction Waste and Residues from Red Ceramic Industry in Alternative Mortars

The use of residential construction wastes and residues from the red ceramic industry in alternative mortars was studied. Specifically, the influence of the surface area of these residues, determined by the Blaine method, and the mechanical behavior of those mortars were investigated. The materials are two hydrated limes and four pozzolanas (a red ceramic residue from bricks and tiles, two residential construction wastes, and one artificial pozzolana). These materials were characterized using studies of chemical composition, thermal differential analysis, and x-ray diffraction. The wastes were ground to obtain a distribution of surface areas and pozzolanic activities (determined by consumption of lime). Alternative mortars were prepared in the ratio of 1:3 by weight (cement/aggregate). For lime pozzolana cement, compositions of 30–70, 40–60, and 50–50% of lime and pozzolana were used. The specimens were cured for periods of 7, 28, and 60 days and the unconfined compression strength (UCS) was determined. The results showed high recycling viability of solid residues and a significant increase in UCS of the mortars with increasing surface area of the residue samples.     

Defect Costs in Residential Construction

The residential construction industry is an important contributor to the Australian economy; the industry employs a very large component of the national workforce, and yet the industry is plagued by defective work and poor quality. Previous research has revealed that defects and rework are endemic in the residential sector. In an attempt to quantify the degree of defects being experienced in new residential construction this paper provides an analysis of defects that were recorded by a government-owned housing insurance organization, the Housing Guarantee Fund. This research represents one of the most comprehensive research studies of building defects undertaken to date in Australia. The data used were not based on a sample like previous studies but instead represent all new houses constructed in Victoria, Australia between 1982 and 1997. An analysis of the data revealed that one house in eight reported defects, and that the cost of rectification was 4% of the construction contract value. The paper discusses the nature of the most important defects and investigates the impact of contractor type and building type.     

Height and Construction Costs of Residential High-Rise Buildings in Shanghai

A widely recognized theme of construction economics suggests that the cost of construction per square meter increases as building height rises. However, over a number of years, research conducted regarding the height and cost issue has established a classic relationship between the two factors which can be represented by a U-shaped curve. This paper describes the study of the height-cost relationship of high-rise residential buildings in Shanghai in terms of the total construction cost and elemental costs while considering the context and commonality of buildings. This research was developed as an extension of the previous work, which examined data for buildings in Hong Kong. Initial findings indicate that the curves illustrating the relationships between height and cost of residential buildings in Shanghai and Hong Kong exhibit different profiles. The dissimilarities indicate that different sets of criteria should be applied in the judgment of height that affects cost in different locations. In terms of elemental costs, the findings suggest that there are differences in the way these costs react to changes in the building height.     

Drivers for Cost Estimating in Early Design: Case Study of Residential Construction

This paper proposes the use of a series of independent variables for an early estimation of the building construction cost of residential buildings. Based on 70 German residential properties, these variables serve as the cost drivers of a project, and the regression model, tested against the 70 properties, has a mean absolute percentage error of 9.6%. When applied to predict the cost of five more properties that were excluded from the 70 in the regression model, the percentage error ranges between–12 and 13%. The identified cost drivers are: compactness of the building, number of elevators, size of the project, expected duration of construction, proportion of openings in external walls, and region.     

Integrating Neurofuzzy System with Conceptual Cost Estimation to Discover Cost-Related Knowledge from Residential Construction Projects

Cost estimation during early stage of a building construction project plays an important role for feasibility analysis in the planning and design phase. Traditional knowledge-based approaches suffer an essential difficulty due to resource price fluctuation in the market. This paper presents a hybrid method that integrates the principal items ratio estimation method with the adaptive neurofuzzy inference system for mining of cost estimation data. The proposed method provides exceptional capability for mining estimation knowledge that is difficult to be discovered by traditional knowledge-based approaches. A case study of residential building projects in China is conducted to demonstrate the proposed method. The testing results show that the proposed method does not only achieve high estimation accuracy, but also provide desirable features for estimators, such as explicit fuzzy decision rules and graphical presentations.     

Multiscale Nonlinear Framework for the Long-Term Behavior of Layered Composite Structures

This paper presents an integrated micromechanical–structural framework for local–global nonlinear and time-dependent analysis of fiber reinforced polymer composite materials and structures. The proposed modeling approach involves nested multiscale micromodels for unidirectional and continuous filament mat (CFM) layers. In addition, a sublaminate model is used to provide a three-dimensional (3D) effective anisotropic and continuum response to represent the nonlinear viscoelastic behavior of a through-thickness periodical multilayered material system. The 3D multiscale material framework is integrated with a displacement-based finite-element code to perform structural analyses. The time-dependent responses in the unidirectional and CFM layers are exclusively attributed to their matrix constituents. The Schapery nonlinear viscoelastic model is used with a newly developed recursive–iterative integration method applied for the polymeric matrix. The fiber medium is linear and transversely isotropic. The in situ long-term response of the matrix constituents is calibrated and verified using long-term creep coupon tests. Good prediction ability is shown by the proposed framework for the overall viscoelastic behavior of the layered material. Material and geometric nonlinearities of I-shape thick composite columns, having vinylester resin reinforced with E-glass unidirectional (roving) and CFM layers, are studied to illustrate the capability of the multiscale material-structural framework. Nonlinear elastic behavior and creep collapse analyses of the I-shape column are performed. The recursive–iterative and stress correction algorithms, which are implemented and executed simultaneously at each material scale, enhance equilibrium and avoid misleading convergent states.     

Two-Phase Composite Model for High Performance Cementitious Composites

This paper presents a new constitutive model for fiber reinforced cementitious composite materials (FRCC), which is particularly suitable for High Performance Cementitious Composites (HP2C). The model is a two-phase composite model, one phase presenting the matrix, the other the composite fibers. In addition, the matrix–fiber interaction is taken into account as internal cross effects (i.e., thermodynamic couplings) between the irreversible deformations of the composite constituents. From one-dimensional thermodynamics, the partial stresses in the matrix and fibers are derived as thermodynamic forces associated with the irreversible deformations of matrix and fibers, respectively. Next, the identification of the model parameters from tensile data is detailed. In particular, it is shown that the model allows quantification of the ductility enhancement of HP2C in comparison with ordinary FRCC, through two material parameters derived from the constitutive model: a matrix–fiber coupling modulus and a friction-to-fracture strength ratio, to which we refer as ductility ratio. The physical significance of these model parameters is discussed in the context of micromechanical theory. The coupling modulus is found to depend mainly on the fiber volume fraction and the matrix quality. The ductility ratio depends on four material design parameters, which are intrinsic to the matter, and which are not affected by structural size effects. We conclude that any ductility gain, which can be obtained through the use of HP2C, is only related to the mix design, and not to structural dimensions.     

Production System Loading–Cycle Time Relationship in Residential Construction

Production home building possesses characteristics similar to manufacturing processes, such as the construction of more or less similar houses repeatedly and a growing demand for mass customization of homes. As a result of these similarities, larger homebuilders often attempt to view their production system as an assembly line process. However, the management tools generally utilized by these home builders are those used in other sectors of the construction industry, such as critical path method scheduling, cost estimating, and earned value analysis. These management tools do not provide an explanation or control/prediction tools for many undesirable situations that arise during home building, such as increasing cycle time which slows delivery of product to consumers and increases project capital costs, and increasing amounts of work in process that increases capital investment and thereby decreases company financial performance. In order to bring better management tools to the residential construction industry, this study examines relationships between cycle time, work in process, system throughput, new construction starts, and the capacity of the production system using building permit data for new single family homes in Chandler, Ariz. The applicability of Little’s law, a basic equation used in factory production management models, to a residential production system is examined. This study shows a definite, predictable relationship between cycle time, work in process, and production system throughput. It provides a pathway for further study of production system characteristics that have historically not been included in construction management models, with the expectation of developing new construction management tools that will account for more of the characteristics of construction production systems that affect project performance and company financial performance.     

Potential Construction Applications for Thermoset Composite Scrap Material

Thermoset composites are types of advanced plastics that perform well in high temperatures and pressures, can achieve tensile strengths similar to carbon steel, and have suitable electrical resistance properties. Because of these characteristics, engineers are increasing their use in the designs of both mechanical and electrical products, thus increasing the amount of thermoset scrap material sent to landfill sites (estimated to be approximately 1.2 billion kg per year (920,000 t). As a way to reduce the amount of this scrap material taken to landfill sites, possible construction applications are being investigated. Using American Society of Testing and Materials standards, a better understanding of its material properties are being explored, such as strength, density, uniformity, chemical resistance, and impact resistance. One potential application, developed and tested for its suitability as a construction material, was as a flooring substitute for traditional ceramic tile.     

Strengthening Masonry Arches with Composite Materials

The aim of this study was to compare the effects of strengthening masonry arches using two different composite materials. To this end, an experimental analysis was carried out on models of arches that were first damaged, then strengthened by applying composite material sheets to the surface of the intrados, and last, subjected to a loading process until the point of collapse. One arch was strengthened with carbon fiber-reinforced polymer, the other with glass fiber-reinforced cement matrix. Results collected during the experimental analysis were significant in assessing the capability to support horizontal load, in increasing the collapse load, stiffness, and ductility, and in assessing the different fracture patterns and collapse modes of the arches strengthened with different fiber-reinforced composites. The comparison will be useful for establishing the physical-mechanical and aesthetic compatibilities between the original construction and the strengthening matrix (polymeric or cementitious), particularly with reference to the safeguarding of historical buildings.     

Light-Weight Fiber-Reinforced Polymer Composite Deck Panels for Extreme Applications

Currently within the military there is a need for a universal light-weight bridge deck system capable of supporting extreme loads over a wide temperature range. This research presents the development, testing, and analysis of five different fiber-reinforced polymer (FRP) webbed core deck panels. The performance of the FRP webbed decks are compared with an existing aluminum deck and with a baseline balsa core system, which has previously been tested as part of the development of the composite army bridge for the US Army. The study shows that for one-way bending, the FRP webbed core can exceed the shear strength of the baseline balsa core by a factor of 3.2 at a core’s density, which is 28% lighter than the balsa baseline. In addition, weight savings in excess of 30% are shown for using FRP decking in place of conventional aluminum decking. Based on test results and finite-element analysis, the failure modes of the different FRP webbed cores are discussed and design recommendations for FRP webbed core decks are provided.     

Analysis of Residential Framing Accidents, Activities, and Task Demands

Framing contractors have the highest rate of nonfatal incidents among specialty contractors. This case study analyzes 654 safety incidents that occurred over a period of 5??years in a large residential framing company. Accident analysis and interviews with safety and production experts identify the high-risk tasks, the errors that lead to incidents, and the task factors that increase the likelihood of incidents. The analysis resulted in a framework of five task factors that increase the task demands: (1) working platform constraints; (2) ergonomic postures constraints; (3) material/load handling requirements; (4) tool use/accuracy requirements; and (5) difficulties due to external forces. The combined effect of these factors determines the task difficulty and the likelihood of incidents. The paper discusses safety measures to reduce the task demands of the high-risk tasks, as opposed to measures that reduce exposure or mitigate the consequences. Reducing task demands can reduce the likelihood of accidents while at the same time increasing productivity. For practitioners, the study points to the need to understand the high-risk tasks and reduce task demands in their operations. The framework of the five task demand factors provides the “building blocks” of task difficulty for framing tasks and provides directions for further research in understanding and mitigating the combined effect of the task demand factors.     

Lean Management Model for Construction of High-Rise Apartment Buildings

Execution of the finishing works in high-rise apartment buildings is made complex by the need to customize apartments to the varying requirements and designs of individual clients. The conventional construction planning practice of progressing upward from floor to floor breaks down in the face of the arbitrary sequence in which clients finalize their decisions. The results are long cycle times for delivery of completed apartments and corollary high levels of work in progress, budget and schedule overruns, and general dissatisfaction with the process on the part of the developer, contractor, subcontractors, and the clients. Application of lean construction principles to this problem has led to development of a management model that adopts pull scheduling, reduced batch sizes, and a degree of multiskilling. The main benefits expected are an enhanced ability to provide customized apartments, improved cash flow, and reduced apartment delivery cycle times. The model was first formulated in theory, then tested using a management simulation game and computer simulation, and subsequently, developed for practical application. This paper presents an analysis of conventional practice, the theoretical background to the lean approach, and the specific management changes proposed.     

Variable Strain Ductility Ratio for Fiber-Reinforced Polymer-Confined Concrete

The encasement of concrete in fiber-reinforced polymer (FRP) composite jackets can significantly increase the compressive strength and strain ductility of concrete columns and the structural system of which the columns are a part, be it a building or a bridge. Due to the approximate bilinear compressive behavior of FRP-confined concrete, analysis and design of FRP-confined concrete members requires an accurate estimate of the performance enhancement due to the confinement provided by FRP composite jackets. An analytical model is presented for predicting the bilinear compressive behavior of concrete confined with either bonded or nonbonded FRP composite jackets. This article describes the basis of the model, which is a variable plastic strain ductility ratio. The variable plastic strain ductility ratio defines the increase in plastic compressive strain relative to the increase in the plastic compressive strength of the FRP-confined concrete, which is a function of the hoop stiffness of the confining FRP composite jacket, the plastic dilation rate, and the type of bond between the FRP composite and concrete.     

Interface Shear Connection Analysis of Ultrahigh-Performance Fiber-Reinforced Concrete Composite Girders

The purpose is to analyze the interface shear connection behavior for ultrahigh-performance fiber-reinforced concrete (UHPFRC) and normal concrete (NC) composite girders. The shape and dimension of the shear stud in the conducted tests are referenced from the traditional interface connection design and engineering experiences. The interface shear connection parameters, i.e., initial stiffness and slippage capacity of a single shear stud, are measured from three groups of lateral direct push test specimens with different numbers of studs. Based on the UHPFRC tensile failure characteristics and cracked section rotational mechanisms of the UHPFRC-NC composite structures with flexural, or flexural and shear failure, the limit state is defined as a full pullout from the bottom fiber of the UHPFRC girders. Pseudostrain hardening behavior of the UHPFRC is simplified as an equivalent rectangular stress block. From this mechanism, the interface equilibrium equations are constituted and the interface shear connection degree of the UHPFRC-NC composite girders is derived. It is recommended that the interface shear connection degree may be used as minimum design standard for UHPFRC-NC composite interface shear connection design.     

Flexural and Shear Rigidity of Composite Sheet Piles

The flexural and shear rigidity of pultruded composite sheet pile panels consisting of E-glass fiber-reinforced polyester are studied in this paper. The analysis consists of an experimental investigation and an analytical modeling to determine the resistance of the sheet pile panels to the deflections for design of composite sheet pile walls. Timoshenko’s beam theory was used to experimentally determine the flexural rigidity (EI) and shear rigidity (kAG) of the panel. Three- and four-point bending tests were performed on six different span lengths and the results were self-compared from the two independent tests. Analytical expressions for the flexural and shear rigidities were derived to allow the prediction based on the layered structure of pultruded shapes. The values computed from the analytical expressions were examined with the experimental results.     

Fiber-Reinforced Polymer Composites for Construction—State-of-the-Art Review

A concise state-of-the-art survey of fiber-reinforced polymer (also known as fiber-reinforced plastic) composites for construction applications in civil engineering is presented. The paper is organized into separate sections on structural shapes, bridge decks, internal reinforcements, externally bonded reinforcements, and standards and codes. Each section includes a historical review, the current state of the art, and future challenges.     

Measurement Techniques for Estimating Local and Total Duct Leakages in Residential Buildings

The paper proposes two measurement techniques for estimating the duct leakage in residential buildings. The first technique determines the “local” leakages using commercially available zone bags and it is called the zone bag-based measurement technique. Zone bags are used to block the flow of air in ducts so that portions of the duct can be isolated and pressurized separately to measure the respective leakages. The thrust of this technique is to locate where these potential leaks are in the duct system and try to provide more cost effective ways to remedy those leaks than what is available currently. The other technique determines the “total” supply and return leakages using a simple model and it is called the model-based measurement technique. The model is based on pressure drop measurements between the return and supply sides. The proposed techniques were evaluated and validated at the air duct leakage laboratory which has two different air duct configurations and a wide range of leakage levels controlled by holes created at several locations of ductwork. Experimental results indicate that the zone bag-based measurement technique estimates the local leakage accurately with a mean absolute difference of 0.26% of total air-handler flow compared to the baseline. It can be inferred that this method gives a better estimate of the total leakage based on the location of the leak than the duct pressurization method that uses the half plenum pressure technique. The results also show that the model-based measurement technique is a good alternative when one cannot use a physical barrier between the return and supply sides. It was found that the total supply or return side leakage was estimated with a mean absolute difference of 0.6% compared to the baseline technique. The future research step is field testing techniques to examine how one can more efficiently sample the duct system by judicially sectioning off the duct at a few points to obtain localized leakage information and obtain enough information to correct leak problems.     

Composite Tube Hinges

This paper is concerned with self-powered, self-latching tube hinges, made by cutting three parallel slots in a thin-walled carbon fiber reinforced plastic tube with a circular cross section. Thus, a hinge consists of two short tubes connected by three transversally curved strips of material (known as tape springs). A particular tube hinge design is considered, with a diameter of about one-third that of the hinges used previously; this requires the tape springs to reach strains close to failure when the hinge is folded. Three analyses of the peak strains in a tube hinge are presented. The first analysis obtains general analytical expressions for the longitudinal fold radius of a tape spring and the associated peak fiber strains. The second analysis is a finite-element simulation of the folding of a single tape spring and the third analysis is a simulation of a complete tube hinge. It is found that the largest fiber strains in one- and two-ply hinges can be predicted analytically with very good accuracy. It is also found that the contact and interaction between the three tape springs that form a tube hinge, modeled in the third analysis, do not affect the peak strains significantly.     

Dynamic Response of Three Fiber Reinforced Polymer Composite Bridges

Fiber reinforced polymer (FRP) composite bridge decks are gaining the attention of bridge owners because of their light self-weight, corrosion resistance, and ease of installation. Constructed Facilities Center at West Virginia University working with the Federal Highway Administration and West Virginia Department of Transportation has developed three different FRP decking systems and installed several FRP deck bridges in West Virginia. These FRP bridge decks are lighter in weight than comparable concrete systems and therefore their dynamic performance is equally as important as their static performance. In the current study dynamic tests were performed on three FRP deck bridges, namely, Katy Truss Bridge, Market Street Bridge, and Laurel Lick Bridge, in the state of West Virginia. The dynamic response parameters evaluated for the three bridges include dynamic load allowance (DLA) factors, natural frequencies, damping ratios, and deck accelerations caused by moving test trucks. It was found that the DLA factors for Katy Truss and Market Street bridges are within the AASHTO 1998 LRFD specifications, but the deck accelerations were found to be high for both these bridges. DLA factors for Laurel Lick bridge were found to be as high as 93% against the typical design value of 33%; however absolute deck stress induced by vehicle loads is less than 10% of the deck ultimate stress.