Concrete Construction Research Articles

The Gerber bridges in Italy: retracing history to safeguarding existing infrastructures

The static scheme of the Gerber beam was formalized in 1886 when the Bavarian engineer Heinrich Gerber (1832-1912) filed the patent “Balkentrager mit freigenden Stuntzpunkten,” introducing the concept of internal hinges within the continuous girder static model. By the 1890s, large metal viaducts constructed applying the Gerber scheme became widely adopted. Subsequently, from around 1930 onwards, the Gerber scheme was extended to reinforced concrete bridges. In Italy, the Gerber scheme was widely applied to reinforced concrete bridges from the 1930s to the 1970s. In this context, the Gerber scheme evolved with the technological advancements in reinforced concrete construction, adapting to the gradual integration of prefabrication techniques, prestressing methods, and the industrialization of castings. The present paper retraces the evolution of the reinforced concrete Gerber bridge in Italy, proving the knowledge base framework for the actual assessment and maintenance intervention on existing bridges.

A concrete construction of a topological operator in factorization algebras

Abstract Factorization algebras play a central role in the formulation of quantum field theories given by Kevin Costello and Owen Gwilliam. In this paper, we propose a concrete construction of a topological operator in their formulation. We focus on a shift symmetry of a one-dimensional massless scalar theory. And we give some discussions of $\mathbb {Z}$-gauging of it, i.e., compact scalar theory and its θ-vacuum.

Enhancing sustainability in concrete construction: Utilizing copper slag for improved properties of geopolymer concrete

Geopolymer concrete (GPC), utilizing aluminosilicate precursor materials as binders, stands as an eco-friendly alternative to Portland cement concrete. These precursors commonly include natural resources like metakaolin, volcanic ash, and industrial solid waste such as fly ash (FA) and ground granulated blast furnace slag (GGBFS). However, despite not utilizing cement, GPC still faces environmental challenges due to the use of natural aggregates, leading to resource depletion. To mitigate this issue, researchers have explored replacing natural aggregates with waste materials, aiding both resource conservation and waste management. Copper slag (CS) is one such waste material with potential as fine aggregate in GPC. This study conducts a comprehensive evaluation of FA-GGBFS-based GPC incorporating CS as fine aggregate, revealing notable enhancements in transport, durability, and strength properties. The optimal replacement of 60 % natural sand with CS in GPC resulted in a 20–25 % increase in compressive strength, a 10–15 % improvement in slake durability, an 18–40 % reduction in water absorption, a 30–39 % decrease in permeable voids, and a 26–47 % reduction in depth of wear, all in comparison to the control specimen made with natural sand only. Thus, incorporating CS as a fine aggregate in GPC is recommended as an effective approach to enhance mechanical performance and durability, while contributing to sustainable construction practices.

Understanding the time-dependent rheological behavior of seawater mixed cement paste with fly ash

Due to the relative scarcity of freshwater resources in coastal regions, the use of seawater in concrete construction has great potential due to its benefits in cost and resource. To further advance the application of seawater concrete, a deeper understanding of its rheological properties is essential. This study investigates the effects of fly ash on the time-dependent rheological behavior of seawater cementitious paste, such as yield stress, plastic viscosity, and structural build-up rate. The underlying mechanisms are analyzed using the theories of water film thickness (WFT), ion concentration, and hydration heat. The research findings confirm that the rheological parameters of seawater paste are generally higher than those of deionized water paste, regardless of the cementitious compositions. As fly ash content increases, the plastic viscosity of seawater paste increase, while the fluidity and dynamic yield stress decreases. Further analysis reveals that the decrease in the yield stress with fly ash content is well related to the increase in the WFT, but it cannot sufficiently explain the change of yield stress over time. Instead, the amount of hydration products in seawater paste shows a linear increasing relationship with the dynamic yield stress at 65 min. By contrast, the plastic viscosity can be related to the ion concentration in the interstitial solution, wherein an increase in the concentration of Ca2+ corresponds to an increase in the plastic viscosity. Moreover, the rheological parameters increase over time, with the growth rates between 5 and 35 minutes being higher than those between 35 and 65 minutes, possibly due to the rapid early hydration of the binder materials. This study offers a fundamental theoretical support for the use of seawater in various concrete applications.

Exploring the viability of copper slag geopolymer concrete in structural applications: A study on strength variability and seismic risk assessment

This study explores the use of copper slag (CS) as a sustainable alternative to natural sand (NS) in geopolymer concrete (GPC) for structural applications. Despite the potential of CS to promote environmental sustainability by repurposing industrial waste, its adoption in the construction industry remains limited. To address this gap, the study focuses on two main aspects: (i) modelling the uncertainty in the strength properties of CS-based GPC, and (ii) assessing the performance of CS-based GPC in seismic-resistant reinforced concrete (RC) framed buildings. The results show that the compressive strength of CS-based GPC is best represented by the Gumbel max and Gamma distributions, while the splitting tensile strength is well-modelled by Gamma and lognormal distributions. The flexural strength follows Gumbel max and Weibull distributions. These findings provide valuable data for probabilistic structural analysis and reliability-based design. Additionally, the seismic performance of RC frames made with GPC containing CS was found to be comparable to that of control frames with NS, confirming the viability of CS-based GPC in seismic-resistant structures. This research demonstrates that CS can be effectively utilized in GPC without compromising structural safety, contributing to more sustainable concrete construction practices.

Determination of the moment–rotation relation of continuous timber–concrete composite floors based on the component method

Timber–concrete composite (TCC) combines the advantages of timber and reinforced concrete construction. In multi-storey buildings, the design of TCC floors is often governed by the deformation serviceability requirements. One way to improve deformation serviceability is through the design of continuous floor systems. However, the current practice of TCC slab systems is often limited to load-carrying as single-span beams. This paper presents an analytical model based on the component method for determining the moment–rotation relation of continuous TCC slabs in the range with negative bending moments. The investigations involve the development of load–displacement curves for the individual force-transmitting components, including timber and reinforced concrete, followed by their assembly into a component model. The model has been verified using finite element calculations and the results demonstrate that the moment–rotation relation of continuous TCC systems can be accurately captured. As the variability of the material properties strongly influences the stiffness of the joint and therefore the deformation and stresses in the TCC slab, a probabilistic analysis of the material parameters was performed using the Monte Carlo method. The probabilistic investigations show that the variability of the input parameters has a significant impact on the joint stiffness, with notable scattering observed in the moment–rotation relation, especially in the range of the cracking phase of the concrete. The results from the probabilistic investigations enable initial statements about the joint stiffness of continuous timber–concrete composite slabs in ranges with negative bending moments.

An investigation of palm oil fuel ash and limestone powder for use in sustainable high strength concrete construction

This study deals with the production of concrete with low CO2 emissions. For this reason, two materials, namely palm oil fuel ash (POFA) and limestone powder (LP), were used as mineral additions to replace conventional cement as much as possible. The results showed that concrete containing 60 wt% POFA could achieve the high strength requirements of ACI 363R from an age of 28 days. At a replacement level of 70 wt% of admixtures, the use of 10 wt% LP + 60 wt% POFA was a good mixture as it had the highest concrete compressive strength, had a minor effect on shrinkage strain and reduced heat generation by approximately 50% compared to cement concrete. Additionally, the use of POFA and LP is a good choice to produce environmentally friendly concrete, which can reduce the CO2 emissions of concrete by about 44–62% compared to cement concrete at similar strength.

Analysis and Design of Pre-Engineered Industrial Warehouse Building with Different Standard

Over the years, pre-engineered building (PEB) has emerged as a sustainable alternative to conventional concrete construction as well as conventional steel construction. In this paper, pre-engineered industrial warehouse building will be design with different codal provision using software Staadpro and analyzed with different loads on building i.e. dead load, live load, collateral load, wind load and load combinations on building .The main objective of this study to find the optimum weight of steel quantity in building with use of different country codel provision .

Improved prediction accuracy for compressive strength of recycled aggregate concrete using optimization-based algorithms and cascade forward neural network

This study proposed a data driven approach to predict the compressive strength (CS) of recycled aggregate concrete (RAC) for sustainable construction using an elite single genetic optimization algorithm-based cascade forward neural network (ESGA-CFNN) model. It was applied to 272 RAC samples under different conditions and compositions focusing on key parameters for CS prediction: water-to-cement ratio (WCR), water absorption (WA), recycled coarse aggregate (RCA) density, fine aggregate (FA) density, naturally occurring coarse aggregate (NCA) density and water-to-total material ratio (WTMR). These parameters were used to develop the ESGA-CFNN model which was then evaluated for its performance. To compare the ESGA-CFNN model, two other models were developed and compared: particle swarm optimization-based CFNN (PSO-CFNN) and artificial bee colony-based CFNN (ABC-CFNN). K-fold cross-validation was used during model development to prevent overfitting. Results showed that ESGA-CFNN model performed better with an RMSE (root-mean-squared error) of 1.144, R2 (determination coefficient) of 0.991 and a10-index of 1.000. ABC-CFNN model had an RMSE of 1.434, R2 of 0.987 and a10-index of 0.982 while PSO-CFNN had an RMSE of 1.561, R2 of 0.984 and a10-index of 0.982. Practical validation with 6 RAC samples confirmed the real world applicability of these models. The findings of this study showed that the proposed ESGA-CFNN model is important for quality control in RAC production and optimizing mix designs to achieve required compressive strength to meet standards and reduce cost and increase sustainability in concrete construction. This study introduces a novel hybrid approach combining ESGA-CFNN, PSO-CFNN, and ABC-CFNN algorithms for accurately predicting the compressive strength of RAC. These models outperform traditional methodologies by offering enhanced predictive accuracy and generalization capability, especially in complex, real-world datasets.

Multi-functional additively constructed honeycomb walls for housing and sheltering

Honeycomb designs have become increasingly popular in additive manufacturing due to their great mechanical properties. The honeycomb infill pattern has allowed the creation of lightweight objects without sacrificing the strength of solid objects. Honeycombs have been utilized in different applications, including architecture, aerospace, and automotive. However, there is a lack of honeycomb designs within the construction industry. With the growth of concrete additive construction, there is an opportunity to introduce honeycomb designs into construction practices. This paper proposes a methodology for manufacturing multi-functional walls through additive construction. The methodology includes several key steps, from material development and quality control testing to wall assembly and experimental investigation. Two multi-functional wall segments were additively constructed, reaching a height of 1180 mm, a width of 610 mm, and a thickness of 90 mm. These measurements led to the manufacturing of seven distinct cellular sections per wall, comprising three main, two intermediate, and two end cellular units. In addition, a columnar unit was additively constructed for corner connection, featuring two vertical octagonal cells with end brackets. A preliminary wall system made up of honeycomb wall segments was assembled using various additional materials such as sealant, clamping systems, and insulative materials. Furthermore, an additional wall segment with end connections was designed and manufactured to test its load-carrying capacity. The wall segment performed well compared to wooden stud walls and showed sufficient load-carrying capacity. Unlike traditional un-reinforced concrete structures, which are brittle and experience small plastic deformations before failing, the honeycomb wall structure experienced large plastic deformation before failure due to the use of insulation foam and silicon rubber. The preliminary testing showed that the honeycomb wall system could be an alternative to traditional housing construction, especially for shelters.

Simulation and Deformation Analysis of Construction Process of Large Eccentric Frame‐Core Tube Structure

ABSTRACTThe large eccentric frame‐core tube structure may generate nonnegligible horizontal deformation in the eccentric direction during the construction process, which should be given due attention. The construction process of a 388‐m‐high super high‐rise structure was simulated with the effects of concrete properties and construction processes. The reinforcement effect of steel bar in reinforced concrete shear wall and the hoop effect of steel tube in concrete filled steel tube (CFST) columns were considered by using the two‐cell simulation method, respectively. The accuracy of the finite element model was effectively verified based on the measured data under different construction process. The results show that the construction process has a large influence on both the vertical and horizontal deformation. The measures of construction leveling effectively reduce the vertical and horizontal deformation of super high‐rise structures, which is important for controlling the structural deformation. The proportion of creep‐shrinkage deformation in the total deformation is large. In this case, the proportion of creep‐shrinkage deformation in the shear wall is 45% to 50%, whereas it is about 30% in the frame columns. The eccentricity caused by floor slab gravity will be mitigated if the construction of the frame slab lags behind the construction of the steel frame, which is beneficial to the control of the horizontal structural deformation. After construction completion, the deformation caused by nonload factors is limited compared to the deformation caused by live loads.

Effect of temperature rise caused by fire on the physical and mechanical properties of concrete

In the past few years, several concrete constructions have suffered major fires, causing very significant damage to the structure. The fire resistance of concrete depends on some of its characteristics such as the nature of the components used for its formulation, permeability, water content and mechanical resistance. In the places most exposed to fire, all the coating can be expelled, which seriously threatens the bearing capacity of the construction. In addition, the financial loss due to repair over a long period can reach several million Euros. This paper presents the physical and chemical transformations caused by the increase in the temperature of concrete in the event of a fire. These transformations mainly have an effect on the microstructure, the mechanical properties and the thermal deformation of concrete. The two phenomena of flaking and spalling of concrete were also studied in order to know their origins and found the methods of preventive. Indeed, flaking can manifest itself explosively, and have significant consequences on the resistance of concrete. It thus reduces the cross-section of the structure and also decreases its bearing capacity, which leads to an increase in the risk of structural failure. The factors influencing the flaking phenomenon were also presented.

Second Life for Recycled Concrete and Other Construction and Demolition Waste in Mortars for Masonry: Full Scope of Material Properties, Performance, and Environmental Aspects

This review presents the scope of current efforts to utilize recycled construction and demolition waste in mortars for masonry. More than 100 articles are divided into groups pertaining to the type of mortar, different binder systems, the type of construction and demolition waste (CDW), and its utilization specifics. Cement-based mortars dominate this research domain, whereas recycled concrete is the main material employed to replace virgin aggregates, followed by recycled masonry and recycled mixed waste aggregates. Such application in cement-based mortars could increase water demand by 20–34% and reduce strength by 11–50%, with recycled concrete aggregates being the most favorable. Natural aggregate substitution is disadvantageous in strong mortars, whereas weaker ones, such as lime-based mortars, could benefit from this incorporation. The extent of this topic also suggests possibilities for different recycled material use cases in mortars for masonry, although the available literature is largely insufficient to infer meaningful trends. Nonetheless, the most relevant knowledge synthesized in this review offers promising and environment-conscious utilization pathways for recycled concrete and other construction and demolition waste, which brings opportunities for further research on their use in mortars for masonry and industrial-scale applications.

Experimental investigation on reducing the interface adhesion of concrete and formwork via electroosmosis approach

Slipform construction is widely used for building deep-buried vertical and inclined shaft concrete linings due to its efficiency and cost advantages. The adhesion of the interface during demoulding is crucial for the efficiency and quality of slip form construction. In this paper, a novel approach is proposed to reduce the adhesion between concrete and formwork based on electroosmotic technology. A self-designed concrete electroosmotic demoulding device was developed to simulate the electroosmotic slip-form construction of the shaft lining. The variations in parameters such as current and permeability during electroosmosis were analyzed, and the impact of electroosmotic parameters on the adhesion and demoulding quality of concrete was investigated. The results indicate that the electroosmotic method can significantly reduce the adhesion. Concrete demoulding defects are significantly reduced and smoother after electroosmotic treatment. This study provides a scientific basis and technical support for optimizing concrete construction demoulding technology.

State-of-the-art of mechanical properties of 3D printed concrete

The utilization of 3D printing in civil engineering has expedited the progression of intelligent construction and building industrialization. A plethora of studies in recent years have contributed to the advancement of 3D printed concrete technology. In contrast to traditional concrete construction techniques, 3D printed concrete technology offers additional benefits such as cost-effectiveness, reduced environmental impact, and a simpler process. The mechanical properties of 3D printed concrete are crucial for its application in building structures. This article provides a comprehensive review of the latest research endeavors in 3D printed concrete, covering both research and application. Firstly, this manuscript examines the size parameters and fabrication methods of the specimens utilized for mechanical performance tests. Subsequently, the mechanical properties of 3D printed concrete are described, and the effect of time-gap as a significant parameter on the performance of 3D printed concrete is discussed. Finally, the existing 3D printed concrete reinforcement technologies and their applications are summarized and categorized based on fibers and steel bars. Moreover, the key technical obstacles in the application of 3D printed concrete in building structures are identified. The ultimate objective of this article is to chart a course for the development and implementation of 3D printed concrete in building structures.

Automatic Design and Monitoring of Mass Concrete Based on Information Technology

Mass concrete construction has the characteristics of large scale, complex technology, high professional requirements, and complex management. In this paper, information technology is introduced into the construction process of mass concrete, aiming to develop a system that integrates the automatic design and visual management of mass concrete construction monitoring schemes to improve its construction efficiency. In this paper, the automatic design of a mass concrete construction monitoring scheme is designed, the information of its data acquisition terminal sensor is extended, and the sensor information model is created based on the IFC framework. Finally, this paper verifies the feasibility and practicability of the automatic design and visual monitoring of the monitoring scheme through the actual case-commercial complex raft foundation. The results show that the method provides a digital and information platform for mass concrete construction, highlighting the advantages of the proposed method and the traditional method.

An Experimental Study and Result Analysis on the Dynamic Effective Bond Length of a Carbon Fiber-Reinforced Polymer Sheet Attached to a Concrete Surface

A carbon fiber-reinforced polymer (CFRP) is a common material utilized for the enhancement in reinforced concrete (RC) constructions. Previous research indicates that the bonding performance between a CFRP sheet and concrete determines whether the bonding of CFRP material is effective. However, the majority of existing research on the bonding performance of the CFRP–concrete interface is concentrated on static loading conditions. In order to clarify the effect of dynamic load on the bonding performance of the CFRP sheet–concrete interface, this study adopts the double-sided shear test method to carry out dynamic experimental research. The test findings reveal that the damage pattern of the CFRP sheet–concrete interface remains consistent across different loading rates. The ultimate bearing capacity increases as the strain rate increases. As the strain rate increases from 10−5 s−1 to 10−2 s−1, the effect of bond length on ultimate bearing capacity increases by about 7%. As the strain rate increases, both the maximum strain of CFRP and the maximum interfacial shear stress demonstrate a corresponding increase, with respective increase rates of 60% and 20%. The effective bond length decreases by about 20% when the strain rate rises from 10−5 s−1 to 10−2 s−1. Finally, a formula for calculating the dynamic effective bond length of a CFRP sheet, grounded in the Chen and Teng formula, has been proposed and verified.

A Mesoscopic Approach for the Numerical Simulation of a Mass Concrete Structure Construction Using Post-Cooling Systems

This study introduces an innovative numerical approach to simulate the construction of large concrete structures incorporating post-cooling systems employing the finite element method (FEM). The proposed methodology integrates critical construction parameters, including temperature control mechanisms, while accounting for concrete hydration and environmental conditions. Compared to traditional discrete models, this approach provides similar accuracy with substantially reduced computational costs, enhancing predictive capabilities in the thermal analysis of mass concrete. The method was applied to simulate the construction of a water intake pillar at the Tocoma hydroelectric plant in Venezuela, where the simulated results closely matched in situ temperature measurements. The findings highlight the method’s efficiency and accuracy in simulating post-cooling systems, offering a practical solution for improving the safety and cost-effectiveness in large-scale concrete construction projects.

Exploring Current Techniques for Improving the Properties of New Concrete

In modern construction, the properties of new concrete are crucial for building quality and structural performance. Recent technological advancements have led to significant progress in enhancing the properties of new concrete. This study employs theoretical and experimental methods to explore the connection among shear stress and shear strain rate under vibration, the impact of aggregate substitution on concrete performance, and the rheological properties of moist shotcrete. The findings suggest that adjusting mix proportions and using additives can significantly improve concrete's strength, durability, and workability. This research provides engineers with a theoretical foundation for optimizing concrete mixtures and construction techniques, thereby improving overall building quality and construction efficiency. The findings suggest that sustainable materials can be used without compromising structural integrity, making the construction process more environmentally friendly while maintaining high performance standards. Furthermore, this study highlights the importance of understanding concrete behavior under various conditions to develop more resilient and long-lasting structures.

Distortion of Magnetic Fields Near a Steel Construction. Modeling

Natural variations of the Earth's magnetic field and its man-made distortions are considered. The rules and regulations in force in the Russian Federation for staying and living in places with a distortion of the Earth's magnetic field are analyzed. Existing methods for eliminating distorted magnetic fields inside residential and work premises are considered. Modeling of distortions of the Earth's magnetic field by building materials was carried out and the influence of their location in space on the overall picture of the resulting magnetic field was shown. To modeling the influence of reinforcement of reinforced concrete constructions on the resulting magnetic field, 6 models of the location of reinforcing bars and their groups were used: one reinforcing bar magnetized against the Earth’s magnetic field and along the Earth’s field; 4 reinforcing bars each, magnetized against the Earth’s magnetic field and magnetized in an alternating manner; the simplest model of a residential structure or public building with 36 reinforcing bars magnetized against the Earth’s magnetic field and with 36 magnetized bars in different directions. Near the model of a rod with magnetization along the Earth’s magnetic field, there are hypogeomagnetic fields. Near the models of a reinforcing bar and four reinforcing bars magnetized against the Earth’s magnetic field, there are no hypogeomagnetic zones and changes in the direction of the magnetic field strength vectors, but strong increases in the resulting magnetic field can be observed - 500 times or more. Near models with 4 reinforcing bars magnetized in an alternating manner, there are the most dangerous zero values of magnetic field strength at a distance of 1 m. Inside the model with 36 reinforcing bars there is a hypogeomagnetic field in the very center of the model and a change in the direction of the magnetic field strength vectors. Near the model with 36 magnetized rods in different directions, a more even resulting magnetic field is observed without sharp changes in its direction and absolute value. Methods have been proposed for eliminating magnetic pathogenic zones at the stages of installation and construction of building that have ferromagnetic materials in their design.