In this study, the tensile strength, failure mechanism and ductile behavior of geo-grid reinforced high strength self-compacting concrete discs subjected to botch of the Brazilian tensile strength test and Biaxial compressive test are studied. To determine the combined effects of geo-grid layer numbers and inclination angle on the ultimate tensile strength of concrete samples, 21 experiments were conducted

A test was carried out to study the interface shear strength between the carbonated concrete substrate and self-compacting concrete (SCC) overlay. One hundred and fourteen Z-type specimens were designed and subjected to the direct shear test. The influence of four interface treatment methods, three strengthening schemes, the SCC strength on the interface shear strength were discussed. Two coefficients

Currently, one of the most important trends in concrete technology is the use of inert fine particles (fillers) to decrease cement content, increase packing in the paste and increase flowability, with gains in technological, environmental and cost aspects. The advance in dispersion technology (using superplasticizers) is one of the technical issues that allow pastes can be mixed without the expected

Vertical porosity profile of Pervious Concrete (PC) is dictated by mix design parameters including Aggregate-to-Cement (A/C) ratio, compaction type and effort. The presented work attempted to reveal the profound impacts of said parameters on porosity and strength. Vertical profile analysis using image processing technique revealed that approximately 10-15 mm thick zone with high porosity was observed

Environmental conditions critically affect the expansion behaviour of concrete due to alkali–silica reaction (ASR) and, therefore, must be modelled to predict ASR-induced expansion behaviour. In addition, laboratory tests are important for the provision of useful data for numerical models, since these models often require the calibration of some unknown parameters according to the materials tested

One of the challenges to reinforced concrete slabs in bridges is deterioration due to rebar corrosion by deicing salts. In order to simulate a concrete slab subjected to deicing salt penetration from the top surface of the bridge slab during winter, high-strength steam-cured concrete with double-layer reinforcements was exposed to 10% sodium chloride solution to investigate rebar corrosion. Five concrete

The construction of high-rise buildings and tunnels necessitates pumping concrete over long distances. Concrete pumping is a complex physico-chemical process that results in the formation of different layers with distinct characteristics inside the pipe. A thin cement paste/mortar layer formed at the concrete–pipe interface, called the lubrication layer (LL), is vital for facilitating concrete pumping

The alkali–silica reaction (ASR) starts with the dissolution of silica in alkali-reactive aggregates. Besides the thermodynamic basics of silica dissolution, kinetic data are needed to model ASR in order to describe the temporal course of the reaction. Although the dissolution kinetics of silica has been investigated frequently, data for concrete-like environments (pH > 12) and under special influences

The purpose of this study is to evaluate the influence of cation types on the rust resistance performance of new nucleic acid corrosion inhibitors in simulated concrete pore solution. Four common chlorinated ice salts (sodium chloride (NaCl), potassium choride (KCl), calcium chloride (CaCl2) and magnesium chloride (MgCl2)) were selected to study the corrosion behaviour of chloride ions by linear polarisation

With the retirement of coal-fired power stations, wet-stored stockpile fly ash is increasingly being considered for use in concrete. A key property of dry fly ash in this application is air entrainment, which can be affected by unburnt carbon present, influencing bubble stability and air-entraining admixture (AEA) dose requirements. Preliminary tests suggest wet storage can influence the process and

A novel theoretical model capable of quantifying the stress causing transient thermal strain (TTS) in heated concrete is presented. It is applicable to numerical models and as a design equation for assessment of stress caused by combined actions of loading, heating fluxes and end restraints during heating. Three categories of concrete members are classified: heated then loaded; loaded then heated;

Concrete compressive strength is one of the most important material performance indices which can reflect the quality of concrete materials. In this paper, an innovative test method is proposed for monitoring development of concrete compressive strength in full curing period using smart piezoelectric modules (SPMs). The proposed method overcomes the shortcomings of traditional concrete detection methods

This investigation explores the structural performance of glass-fibre-reinforced polymer (GFRP)-reinforced concrete columns incorporating hybrid fibres (GHFRC columns) under different loading conditions. The hybrid-fibre-reinforced concrete consisted of two kinds of fibres (steel and polypropylene). A total of nine GHFRC specimens with a diameter of 250 mm and a height of 1150 mm were fabricated and

This paper presents an experimental study on the effects of lateral tension and loading rate on the local bond performance of ribbed bars in concrete. In the experiment, three kinds of concrete, three types of steel bars, five levels of lateral tension, and four loading rates are considered. The results show that up to a loading rate of 10 mm/s, the mode of bond failure is independent of the loading

Based on orthogonal experiments, an ordinary Portland cement (OPC)-fly ash (FA)-silica fume (SF) ternary cementitious material system was developed. The ultra-high-strength lightweight concrete (UHPLC) with a strength exceeding 100 MPa was prepared using pottery sand (PS) and hollow glass microspheres (HGM) as the weight-reducing material and steel fibers as reinforcement. Through workability, apparent

This study examined the effect of the unit weight and compressive strength of concrete on the punching shear capacity of flat slabs without shear reinforcements. The slabs were prepared using all-lightweight aggregate concrete (ALWAC), sand-lightweight aggregate concrete (SLWAC) and normal-weight concrete (NWC) at the different compressive strengths of concrete of 24 and 45 MPa. Based on the upper-bound

A modified applied element model to simulate the behaviour of plain concrete continuum structures including discrete cracking is proposed in this study. In the classical applied element model, Poisson effects are fully ignored. To remediate this issue, diagonal elements are introduced to include the Poisson effect, and the constitutive parameters are rigorously determined using the Cauchy–Born rule

Very few studies have been dedicated to the size effect on the shear behaviour of reinforced concrete (RC) columns. In particular, there lacks a design equation that can quantitatively represent the effect of related parameters on the size effect on nominal shear strength for RC columns. This work presents a mesoscale numerical analysis of the mechanical response of geometrically similar RC columns

Supplementary cementitious materials (SCMs) are widely used to reduce the cement content to achieve economic and environmental objectives. As a result, understanding the shrinkage of blended cement-based concrete is essential. In total, 21 concrete mixes were produced with type general purpose cement and with cement replacements of 30% by fly ash, 40% and 60% by ground granulated blast furnace slag

The purpose of this study is to evaluate the influence of cation types on the rust resistance performance of new nucleic acid corrosion inhibitors in simulated concrete pore solution. Four common chlorinated ice salts (NaCl, KCl, CaCl2, MgCl2) are selected to study the corrosion behavior of chloride ions by linear polarization resistance method, electrochemical impedance spectroscopy and X-ray photoelectron

One of the challenges to reinforced concrete slab in bridge is the deterioration due to rebar corrosion by deicing salts. In order to simulate a concrete slab subjected to deicing salt penetration from the top surface of the bridge slab during winter, high-strength steam-cured concrete with double-layer reinforcements was exposed to 10% sodium chloride solution to investigate rebar corrosion. Five

With the requirements for the ductility, toughness and durability of structures increasing and the promotion of sustainable development, low-cost and high-performance building materials are highly valued by the engineering community. In this work, 12 groups of engineered cementitious composites (ECC) made with polyvinyl alcohol fibre (PVAF) were prepared. The specimens were divided into two test groups

This study investigated the axial compressive behaviours of cement mortar reinforced with crimped shaped memory alloy (SMA) fibres produced by cold drawing. The performance of the crimped fibre was investigated in term of tensile behaviour, deformation recovery, recovery stress and pullout behaviour. After that, compressive tests of mortar reinforced with two types of SMA fibres, namely, dog-bone-shaped

The electrochemical tests commonly used for evaluating reinforcement corrosion in Portland cement-based concrete may not be appropriate for testing alkali-activated slag (AAS) concrete due to its different pore structure and pore solution composition. In this article, corrosion behaviour of the steel bars in 12 AAS concrete mixes with different alkali concentration and modulus of sodium silicate solution

Sustainable development relies on efficient energy consumption and environmental protection. The construction industry accounts for a significant portion of global energy consumption. Concrete, as the most commonly used construction material, can play an important role in reducing global energy consumption owing to its thermal properties and its capacity for using waste materials as mix ingredients

This paper proposes three new types of connectors adopted in discrete connected new-type precast concrete diaphragms (DCNPD). An experimental investigation of innovated connectors under shear load was conducted to evaluate the failure mode, strain and bearing capacity of joint connections in DCNPD. Based on the experimental results, the hairpin connector (HPC) was selected for simulation verification

A reasonable assessment of the probability of structural failure is essential to ensure the safe performance of corroded reinforced concrete (RC) structures. In this paper, a novel cross-sectional area loss model of corroded steel bars is proposed and the scale of fluctuation of some key parameters is estimated using the semi-variogram function method. A stochastic resistance deterioration model considering

This paper reviews and summarises the use of magnesium oxide (MgO) in hydraulic concrete in the following projects in China: Baishan hydropower station unexpectedly discovered the beneficial effects of MgO; Dongfeng hydropower station actively used MgO as an expansive agent for the first time in the main project; Changshaba hydropower station used MgO expansive agent for the first time in a full arch

The effects of graphene oxide (GO) on the microstructure and resistance to chloride ion (Cl−) penetration of matrix containing 0-0.05% GO were investigated through isothermal calorimetry, thermogravimetric analysis, X-ray diffraction, mercury intrusion porosimetry and the rapid chloride penetration test method. A proper dosage of GO promoted the hydration process of cement, increased the calcium hydroxide

The non-linear performance of concrete is determined by the heterogeneous micro-structure of concrete. The existing methods mainly focus on numerical simulation of concrete at meso-scale. In view of this, the micro-calculation model based on bond-based peridynamics (BBPD) was established by the MATLAB-ABAQUS co-simulation method. In this study, based on the concrete plastic damage model in ABAQUS,

The mechanical behavior of 66 carbon-fibre-reinforced polymer (CFRP)-confined concrete-filled steel tubular (CFST) short columns and 42 non-CFRP-confined CFST short columns under axial compression are studied. The typical failure modes and load–displacement curves of the specimen are obtained, and the stress mechanisms of the specimen are analysed. The effects of fiber-reinforced polymer (FRP) layers

Carbon-conditioning or chemical permeation methods can provide excellent microstructural improvements to recycled concrete and brick aggregate; however, the applications have their limitations. Further, recycled brick aggregate cannot be effectively carbon-conditioned with conventional methods as it contains only trace amounts of reactive materials. It is therefore a necessity to use hybrid methods

Image-based deterioration analysis deals with estimating the correlation between the extent of deterioration in terms of changes in colour profiles of deteriorated surfaces with changes in the residual strength and durability. Analysis was performed on images of cubes of concrete immersed in acid, chloride and sulphate at 5% concentration for a period of 3, 7, 14 and 28 days. The colour profiles of

Concrete and cementitious composites have far been the main and most widely used construction materials throughout the world due to their outstanding features, such as high structural properties, accessibility, and relative low production costs. However, these materials are prone to degradation caused either by automatic cracking or external excitations, which leads to structural degradation. The increasing

The test results of five one-tenth scale micro-concrete waffle slabs subjected to edge punching shear in the presence of moment transfer parallel to the slab's free edge are presented. Although the observed punching failure mechanism of the waffle slabs was found to be very similar to that of a flat slab, the shear capacity was reduced because some of the potential failure surface is lost when it extends

The damage rating index (DRI) has proven to be a quite reliable microscopic technique enabling the condition assessment of concrete affected by internal swelling reactions. Yet, very little research has been conducted on the use of the DRI to appraise induced deterioration caused by physical salt attack (PSA) and external sulfate attack (ESA). This study aims to assess the condition of concrete subjected

This study aims to numerically investigate the behaviour of corroded circular reinforced concrete (RC) columns strengthened by carbon-fabric-reinforced cementitious matrix (C-FRCM) composites. Three-dimensional finite element (FE) models of the corroded circular RC columns with and without strengthening were set up and validated against previous experimental results. Based on the validated FE models

Biochar-containing cement composites have attracted increasing interest in recent years due to the possibility of reducing the environmental impact linked to cement. They can also improve the mechanical properties and the electrical conductivity of cement-based materials. One parameter that can affect the mechanical performance of biochar-containing cement composites is the morphology of the biochar

Although recycled aggregate concrete (RAC) has been extensively studied, several critical problems with its fundamental behaviors still urgently need to be figured out. Therefore, this series of two reviews re-thinks fundamental behaviors of RAC based on the latest literature. In the last review (part I), the mechanical and deformation behaviors of RAC were intensively discussed. Here in part II, the

The aim of this work was to find the optimum rheology for maximising the strength of basalt-fibre-reinforced self-compacting mortar (BFRSCM). An experiment was employed to design mixes based on the basalt fibre volume percentage (F), water/binder ratio (w/b) and superplasticiser (SP) dosage. Using an L9 Taguchi array, nine mixes were designed considering combinations of F (0.5, 1.0 and 1.5%), w/b (0

Accurate modelling of transient creep strain (TRC) is crucial for reliable fire performance assessments of concrete structures, since it is the largest strain component for structural concrete subjected to thermal exposure. Nonetheless, the mechanism underlying TRC is still not fully understood and most of the available models were established based on ordinary portland cement concrete. As the most

Steel reinforcement corrosion is becoming a critical issue due to the amount of old buildings still in operation with a high probability of substantial corrosion in their reinforcements. The strength and serviceability of corroded reinforced concrete (RC) slab is remarkably impacted by corrosion. Therefore, it is vital to understand more about the punching shear mechanism of slabs subjected to corrosion

Reinforcement congestion causes problems during construction, including improper concrete pouring and concrete vibration. In this study, the replacement of normal concrete by high-performance fibre-reinforced cementitious composites (HPFRCC) has been investigated in order to reduce the amount of transverse reinforcement and prevent reinforcement congestion in beam–column joints. Uniaxial compression

Water was replaced with raw municipal solid waste leachate in a concrete mix. Compared with the control specimen (prepared with freshwater), the hardened concrete specimen made with 100% leachate and cured in freshwater for 28 days showed reductions of 20% in ultrasonic pulse velocity and 45% in unconfined compressive strength. Scanning electron microscopy revealed that an increase in leachate content

Recent studies have revealed the complex characteristics of cracking torques, Tcr, in prestressed concrete (PC). The distribution pattern of the longitudinal prestressing tendons in the cross-section is an important factor, but it is not considered in any methods. Recent studies have also shown that a PC-Tcr can be expressed in terms of the prestress ratio and a Tcr value calculated using an existing

To better assess the safety of cementitious materials containing crushed waste oyster shells (WOS), the workability, mechanical properties (compressive strength and static elastic modulus) and durability (volume of permeable void (VPV), water absorption (WA) and total charge passed) were studied. The effects of replacing river sand with different content of crushed WOS (0, 10, 20 and 30%) on flowability

In order to provide theoretical guidance for sulfoaluminate cement as grouting material used for coal mines, the purpose of this paper is to trace the hydration process and study the hydration kinetics of sulfoaluminate cement. The influence of the water/cement ratio (W/C) on the hydration exothermic characteristics of sulfoaluminate cement was studied by TAM air hydration microcalorimeter, Raman spectrum

This paper studies the interface bonding performance of carbon-fabric-reinforced cementitious matrix (C-FRCM) composites with the impressed current cathodic protection (ICCP) technique. Single shear tests and pull-out tests on the C-FRCM composites are launched. Three current densities of 0, 100 and 150 mA/m2 in the ICCP technique are considered. The resistance–slip relationships for all the composites

In this study, various dosages of limestone (LS) powder (10, 15 and 20%) of varying fineness were used as a replacement for cement to investigate its influence on the selected properties of high-performance concrete (HPC). The efficiency factor and carbon dioxide (CO2) equivalent emissions were evaluated for life cycle assessment of HPC mixtures containing LS powder. The workability, compressive, split

In this research, the effect of porosity owing to foam on the penetration parameters of foamed concrete, including absorption and chloride ingress, is evaluated. The penetration parameters of foamed concrete are determined using a water/cement (w/c) ratio of 0.5 and foam contents of 20, 35 and 50%, and then compared with the base mix without foam and with an equal w/c ratio. In addition, the penetration

The aim of this study is to investigate the possibility of improving the mechanical properties of mortars produced with waste-based binder and sand by incorporating graphene oxide (GO) nanomaterial. Twenty-seven unique mortars were manufactured by replacing cement with glass powder (GP) and ground granulated blast furnace slag (GGBS), and river sand with lead smelter slag and foundry sand. GO was added

The mechanical and microstructural properties of alkali-activated slag cement (AASC) mixed with 2–10% zinc oxide (ZnO) were investigated. The addition of zinc oxide was found to be more effective for improving the strength at a later age: compared with AASC without zinc oxide, the addition of 10% zinc oxide improved the compressive strength by about 22% at 28 days. Furthermore, through the formation

The present study investigated the effect of the addition of steel fibres (SFs) and the synergy of SFs and carbon nanotubes (CNTs) on the mechanical properties of high-strength concrete (HSC). The addition of CNTs prevents the growth of micro cracks during loading, creates a denser composite and enhances the bond between SFs and cement paste. Three samples of HSC with a compressive strength of 68 MPa

Eight reinforced concrete deep beams with circular or square openings were tested and the results are reported here. The main variables studied were the shape of the openings, the compressive strength of the concrete and parameters for the horizontal stirrups. The test results show that the shear strengths of deep beams made with high-strength concrete were higher than the shear strengths of deep beams

For this paper, the punching shear behaviour of 18 steel-fibre recycled aggregate concrete (SFRAC) balanced slab–column connections was experimentally investigated and analytically modelled for the following variables: the recycled concrete aggregate replacement level (0, 50 and 100%) and the volume fraction of hooked-end fibres (0, 0.4 and 0.8%). The measured punching shear capacities were practically

The compressive stress–strain curves of reactive powder concrete (RPC) reinforced with basalt fibres (BFs) were experimentally studied. The length and volume content of BFs were considered as the influencing parameters. A total of 15 groups of cementitious composite specimens were investigated. The workability, failure mode, peak stress, corresponding strain at peak stress, elastic modulus, toughness

This paper proposes an analytical method for predicting the shear capacity of hybrid fibre-reinforced concrete (HFRC) deep beams based on the softened strut-and-tie model. Moreover, a test was conducted to evaluate the proposed method and further investigate the shear behaviour of HFRC deep beam. The shear and deformation capacities of HFRC deep beams increased with the steel fibre volume. The shear

Incorporating carbon nanotubes (CNTs) into concrete can improve its fracture toughness. The crack resistance properties of reinforced concrete with CNTs were tested by ring test and three-point bending beam fracture test. The fracture parameters of reinforced concrete with CNTs were analysed by using double-K fracture parameters and the results showed that CNTs can improve the crack resistance properties

The application of pretensioned spun high-strength concrete (PHC) piles in high-intensity seismic areas has been limited by insufficient horizontal load resistance and poor deformation capacity. A new type of pretensioned spun concrete pile with high-strength and high-elongation steel strands instead of steel bars has been developed. This paper presents a flexural performance evaluation of the new

An experimental study was conducted to investigate the effects of stirrup corrosion, concrete strength and casting position on the behaviour of the bond between steel bars and concrete. Accelerated corrosion was applied to corrode the stirrups in concrete specimens under laboratory conditions. In total, 180 specimens were cast and tested in this experiment. The specimens had three nominal concrete