Gravel aggregates had been used extensively in the Houston District of Texas Department of Transportation (TxDOT) for continuously reinforced concrete pavements construction for many years. However, some of these pavements have been subject to early age delamination and eventual spalling damage. Therefore, a series of studies funded by TxDOT since the early 1990's has been conducted to gain a better understanding of mechanisms, material properties, and construction practices, and to provide guidelines and recommendations for minimizing early-age delamination in concrete pavements made with gravel aggregates. In this study, a test protocol to measure the bond strength between aggregates and cement mortar was established, and the effects of different material and construction parameters on the bond strength of concrete at early ages using a fractional factorial design were investigated. The significances of each factor to achieve better bonding performance were determined, and the optimum design combination was subsequently chosen and validated. Geometric parameters were proposed to characterize aggregate shape properties relative to bonding performance with the facilitation of the Aggregate Imaging System. A rating system based on utility theory was developed to evaluate the overall contribution of aggregate properties (i.e. physical, geometric, and chemical) to the concrete bonding capability and the feasibility of certain mixture design combinations. As for theoretical representation of the bond strength across the interfacial transition zone, a model of interfacial fracture energy between aggregate and mortar that represents the energy necessary to create a crack along the interface was formulated. This model built the connection between concrete properties at the meso-level (represented by the interfacial fracture energy between aggregate and mortar) and the macro-level (represented by fracture toughness of concrete and significant influencing materials and construction factors). In addition, the moisture effects on stress development of concrete pavements at early ages using field data as inputs were numerically simulated, and a fracture mechanics-based approach was used to predict the occurrence of delamination. A delamination detection protocol for the field was developed to explore the feasibility and potential of utilizing Ground Penetration Radar technology in delamination detection. Research findings from laboratory investigation, field testing, theoretical modeling, and numerical analysis were further validated through field test sections, and the associated framework for delamination guidelines was established.

Non-corroding materials, such as Fibre-Reinforced Polymer (FRP) bars, are now being used as reinforcement for reinforced concrete structures in order to extend their lifetime and minimize maintenance costs. Because of the softer and brittle behaviour of GFRP bars, behaviour of structural members reinforced with this material is different than that of steel-reinforced members. In this study, 16 GFRP reinforced beams were constructed and tested under flexure and shear loads to failure. Effects of different variables, such as amount of longitudinal and lateral reinforcements, type of bars and concrete strength, were investigated for their effects. The flexural provisions of design codes, namely CSA S806-12, CSA S6-06, and report ACI 440.1R-06, were evaluated against the test data. The main provisions investigated are failure modes, ultimate strength, moment-curvature response, deflection, crack widths, and deformability.

Non-corroding materials, such as Fibre-Reinforced Polymer (FRP) bars, are now being used as reinforcement for reinforced concrete structures in order to extend their lifetime and minimize maintenance costs. Because of the softer and brittle behaviour of GFRP bars, behaviour of structural members reinforced with this material is different than that of steel-reinforced members. In this study, 16 GFRP reinforced beams were constructed and tested under flexure and shear loads to failure. Effects of different variables, such as amount of longitudinal and lateral reinforcements, type of bars and concrete strength, were investigated for their effects. The flexural provisions of design codes, namely CSA S806-12, CSA S6-06, and report ACI 440.1R-06, were evaluated against the test data. The main provisions investigated are failure modes, ultimate strength, moment-curvature response, deflection, crack widths, and deformability.

Pervious Concrete Pavement (PCP) has the potential to provide significant benefits. To better understand the technical, economical, and environmental impacts of PCP, the performance must be comprehensively evaluated and quantified. Because PCP is a new material, there is no mechanism for properly quantifying its performance. In addition, the application of this technology in cold climates is limited and therefore limited in-service performance data is available. A comprehensive engineering based performance model quantifies the deterioration rate and predicts future performance. Pavement performance models are developed using a pavement condition index and extensive pavement condition databases. A pavement condition index is a value which expresses the overall condition of pavement by considering various factors such as surface distresses, structural defects, and ride quality. This research will assist pavement engineers and managers in the design, construction, and management of PCP. The review of published literature reveals that there is currently a large gap in the performance evaluation of PCP in cold climates. Neither extensive condition indices nor comprehensive performance models have been developed for PCP. This research involves development of comprehensive performance models for PCP in cold climates using laboratory and field experiments and existing available data in order to predict functionality (permeability rate) and surface distresses of PCP. This study is, furthermore, aimed at developing an extensive condition index for better management of PCP by predicting and quantifying the various types of distresses and the associated functionality of PCP with particular emphasis on cold climate usage and performance. The scope of this research is to design a comprehensive tool which is simple and cost-effective. The tool involves first defining the typical types of distresses that are occurring on PCP. This is facilitated through laboratory and field design, construction, and evaluation of two test sites located in Ontario. It also involves continuous evaluation of these sites and evaluation of several other sites in the United States. The main sources of data in this research are panel rating data and field investigations data. A panel rates the condition of PCP in terms of surface distresses and permeability rates. In addition to this, field measurements of distresses and permeability rates are obtained manually. As a result, the Pervious Concrete Condition Index (PCCI) is developed through incorporation of field measurements and panel ratings. By using regression analysis, performance models are developed between PCCI and pavement age. The performance models are validated using the data splitting technique. Ultimately, the performance models are calibrated using field data by applying the Markov Chain process (acquiring expert knowledge by distributing questionnaires) and the Bayesian technique.

In this work a study has been performed to show the different kinds of insulated balcony connections exists on the market. In the work there is also a short description of thermal bridges concerning balconies. A description of older solutions for balcony connections is given as well as a calculation of the difference in energy costs for a insulated balcony connection compared to the standard connection. The work includes a short description of the different products. After that there is a short information about their insulation properties, durability, acoustic performance, assembly, computer programme and a short analyses for each product.

Pervious Concrete Pavement (PCP) has the potential to provide significant benefits. To better understand the technical, economical, and environmental impacts of PCP, the performance must be comprehensively evaluated and quantified. Because PCP is a new material, there is no mechanism for properly quantifying its performance. In addition, the application of this technology in cold climates is limited and therefore limited in-service performance data is available. A comprehensive engineering based performance model quantifies the deterioration rate and predicts future performance. Pavement performance models are developed using a pavement condition index and extensive pavement condition databases. A pavement condition index is a value which expresses the overall condition of pavement by considering various factors such as surface distresses, structural defects, and ride quality. This research will assist pavement engineers and managers in the design, construction, and management of PCP. The review of published literature reveals that there is currently a large gap in the performance evaluation of PCP in cold climates. Neither extensive condition indices nor comprehensive performance models have been developed for PCP. This research involves development of comprehensive performance models for PCP in cold climates using laboratory and field experiments and existing available data in order to predict functionality (permeability rate) and surface distresses of PCP. This study is, furthermore, aimed at developing an extensive condition index for better management of PCP by predicting and quantifying the various types of distresses and the associated functionality of PCP with particular emphasis on cold climate usage and performance. The scope of this research is to design a comprehensive tool which is simple and cost-effective. The tool involves first defining the typical types of distresses that are occurring on PCP. This is facilitated through laboratory and field design, construction, and evaluation of two test sites located in Ontario. It also involves continuous evaluation of these sites and evaluation of several other sites in the United States. The main sources of data in this research are panel rating data and field investigations data. A panel rates the condition of PCP in terms of surface distresses and permeability rates. In addition to this, field measurements of distresses and permeability rates are obtained manually. As a result, the Pervious Concrete Condition Index (PCCI) is developed through incorporation of field measurements and panel ratings. By using regression analysis, performance models are developed between PCCI and pavement age. The performance models are validated using the data splitting technique. Ultimately, the performance models are calibrated using field data by applying the Markov Chain process (acquiring expert knowledge by distributing questionnaires) and the Bayesian technique.

Anti-icing agents are applied to road surfaces to prevent ice formation and to melt any hail or snow as it falls. The specific agent is selected to provide optimum anti-icing properties for the particular local climate in different municipalities taking into account cost, availability and properties. These anti-icing agents are generally applied in liquid form, and due to their low freezing temperatures, are able to remain liquid at the low ambient temperatures. Unfortunately, the negative aspect of the use of liquid agents is that they are able to penetrate concrete structures to a greater extent than can the solid de-icers, such as rock salt. Once the chloride solutions penetrate the concrete, they can have serious deleterious effects on both the reinforcing steel as well as the concrete [1]. It has been shown in previous studies that the cations of the solutions will tend to react with the cementitious materials to form precipitates of expansive nature. More specifically, the reaction of CaCl2 with Ca(OH)2 results in the formation of expansive calcium hydroxy-chloride [2]. The reaction of MgCl2 with Ca(OH)2 forms Mg(OH)2 in the capillary pores with CaCl2 as a by-product after which the MgCl2 can react with the calcium-silicate-hydrate to form magnesium-silicate-hydrate – a gel-like material with no inherent binding properties or strength. The calcium hydroxy-chloride and Mg(OH)2 precipitates can have a positive effect at early onset, but will eventually cause deterioration of concrete due to the internal forces applied by the precipitates as their volume increases. This can affect the strength and create notable interior strain in the concrete. There are a number of mechanical properties that can be analyzed using short-term testing that will help to determine any changes occurring due to salt solution exposure. To gain a general understanding of the effects of the salt solution exposure in this project, compressive strength, tensile strength, elastic modulus, and strain were measured using a number of exposure conditions. While the results of testing confirm that there are initial benefits beyond minimizing ice formation and bonding, there ultimately exist a number of concerns with respect to the reactions that occur between the salts and hardened cement paste. Although the formation of calcium hydroxy-chloride is known to be expansive [3], evidence of this compound was only seen indirectly through elevated strain and micro-cracking. There was no deterioration of compressive strength, tensile strength, or elastic modulus over the short-term testing. Similarly, and again due to the short testing period, the formation of magnesium-silicate-hydrate (M-S-H) is unlikely to have occurred, though its formation during long-term exposure can result in complete loss of binding strength [2]. However, the precipitation of Mg(OH)2 is believed to be responsible for the lower chloride diffusion rate as well as the increase in strength of the concrete exposed to MgCl2. The only agent which did not yield changes of concern with respect to concrete is the NaCl solution while CaCl2 produced the most deleterious effects.

The students are usually eager to develop their mathematical learning. However, the Skolverket can see that this eagerness passes in the early years of school. A study shows that a varied mathematical education creates enthusiasm to learn, which can decrease the negative view of mathematics. The purpose of this study is to see how five pedagogues use laboratory mathematics, their approaches to laboratory mathematics as well as to find out their role in the laboratory education. The result of the study is based on interviews with the pedagogues, who are all teachers for students in year F-3. All of the pedagogues work in a laboratory way, but to different extents. The study shows that the pedagogues aim to make the mathematics as concrete and everyday as possible. The pedagogues use the laboratory way of working and materials in different ways and have slightly different views of what counts as laboratory material. Further, the study shows that there are more possibilities than obstacles with the laboratory way of working. The five pedagogues all agree that this way of working is beneficial for the pupils, especially for the students who are poor achievers. The possible obstacles raised by the pedagogues were lack of time and to some extend shortage of material. Two important factors within this way of working are communication and briefings.

ABSTRACT Recent years the reducing number of public works projects has been a very serious situation. We had 380 billion and 360 billion projects in 2009 and 2010, in 2011 we only got 180 billion by the big amount of shrinkage of up to as much as 200 billion. In addition, more un-sold houses has been gradually increasing, which makes the relative reduction of the use in concrete can be expected, not even mention the follow-up addition works will be inevitably shrinking. The reduced Shipments plus the up-price of gravel, cement, oil, tires, etc, our industry is forced to raise a lot of the cost. The current situation is extremely unfavorable to the business. The requirements of concrete is being able to reach required strength after 28 days of compressive strength in order to satisfy suppliers and construction companies, in any case the price of course is the first consideration, so the ready-mix concrete companies have price competition in order to get orders, which will cause the poor quality and the shortage of quantity. And this is temporary means of the operation, eventually we will be out of the market by running the business in this way. In the future, I hope to seek the best business strategy through competitive analysis, but also reduce operating costs. As long as we streamline the organization and transformation of the management model, we should be able to get through the crisis, and enhance the industrial competitiveness. Eventually the undesirable industry will be naturally eliminated and the market will back on track.

The close proximity to the New Madrid Seismic Zone and the significant population and infrastructure presents a potentially substantial risk for central U.S. cities such as Memphis, Tennessee. However, seismic provisions in currently adopted Memphis building codes for non-essential structures have a lower seismic design intensity level than the 2003 International Building Code (IBC) with broader acceptance nationally. As such, it is important to evaluate structures designed with these local seismic provisions to determine whether they will perform adequately during two different design-level earthquakes in this region. A four-story reinforced concrete (RC) moment frame with wide-module pan joists was designed according to current building codes relevant to the central U.S.: the 2003 IBC, the City of Memphis and Shelby County locally amended version of the 2003 IBC, and the 1999 Standard Building Code (SBC). Special moment frames (SMFs) were required for the IBC and SBC designs, but lower design forces in the amended IBC case study permitted an intermediate moment frame (IMF). However, the margin by which a SMF was required was very small for the SBC design. For slightly different conditions IMFs could be used. Nonlinear push-over and dynamic analyses using synthetic ground motions developed for Memphis for 2% and 10% probabilities of exceedance in 50 years were conducted for each of the three designs. The FEMA 356 recommended Basic Safety Objective (BSO) is to dually achieve Life Safety (LS) for the 10% in 50 years earthquake and Collapse Prevention (CP) for the 2% in 50 years earthquake. For the member-level evaluation, the SMF designs met the LS performance objective, but none of the designs met the CP performance objective or the BSO. However, the margin by which the SMF buildings exceeded CP performance was relatively small compared to that of the IMF building. Fragility curves were also developed to provide an estimate of the probability of exceeding various performance levels and quantitative performance limits. These relationships further emphasize the benefits of using an SMF as required by the IBC and, in this case, the SBC.