This study investigated the tensile performance of pre-cracked ultra-high performance concrete (UHPC) subjected to sustained loading and various environmental conditions, including air, water, and 3 % NaCl solution. The findings indicated that prolonged tensile loading significantly reduced the tensile properties of UHPC, particularly at higher stress levels. Interestingly, the presence of water and

The disposal of solid and radioactive waste poses significant risks to terrestrial and marine ecosystems. This study presents a sustainable solution by recycling silica-rich glass waste (RG) and fly ash (FA) to develop a functional nanocomposite concrete for radionuclide treatment. A Radionuclide removal Zeolite (RrZ) was hydrothermally synthesized from RG powder at low temperature and NaOH molar ratio

Thermal conductivity of cement composites is crucial for developing various sustainable engineering structures, creating an urgent need to elucidate the influencing factors and their associated mechanisms. Introducing various 0-, 1- and 2-dimensional carbon fillers into traditional cement composites with tailored thermal conductivity demonstrates great potential for practical engineering applications

In order to effectively solve the problem of pollutant degradation in cement-based materials, the BiVO4 was introduced into the reconstruction of the water-encountered MgAl-LDHs layer after calcination utilizing the memory effect of MgAl-LDHs which successfully prepared the highly adsorbable visible light photocatalytic material, BiVO4/MgAl-LDHs. Its layered structure results in a large specific surface

This study aims to enhance the utilization rate of recycled concrete aggregate (RCA) in structural concrete through the application of a novel carbonation treatment method to improve the microstructure of old adhered mortar in RCA and enhance its compatibility with the new concrete. Carbonation of RCA is a commonly used method to densify the microstructure of old adhered mortar, but it exhibits limitations

The current research on the application of nanomaterials in concrete is mainly carried out under positive-temperature curing conditions, while research under negative-temperature curing conditions is very scarce. This paper investigated the effect of nano-SiO2 on long-term strength and chloride diffusivity of cement pastes cured at negative temperature (-5°C). Thermogravimetric analysis (TGA) confirms

Presently, significant attention is directed towards utilisation of recycled plastic waste as an environmentally sustainable substitute for natural aggregate in cementitious concrete materials. This is aimed to bolster the greening endeavours of local construction industry and address the pressing need to improve global plastic recycling rates. Despite extensive literature on different mechanisms underlying

The free CaO (FC) in light-burnt MgO due to the impurity of magnesite ores cannot be avoided, and causes the declination of properties of magnesium oxychloride cement (MOC). In order to clearly explain the declination mechanism of MOC properties due to FC, the effect of FC contents on the formation of phase compositions and the compressive strength of MOC pastes were studied in detail. The findings

Mineral-impregnated carbon fibers (MCF) introduce an innovative reinforcement approach for creating material-efficient structures. Once cured, MCF display a substantially improved bond with the concrete matrix compared to similar polymer-impregnated textiles. Consequently, these novel composites exhibit increased crack density and more uniform crack distribution under uniaxial tensile load. This article

Internal curing and self-compensation are two different approaches to mitigate autogenous shrinkage, with their own pros and cons. In this study, strategies of internal curing and self-compensation are combined in a single material by pre-absorbing hydrophilic carbon nanotube sponge with L-Serine based carbamate (H-CNTSP@C-Ser). In contrast to the detrimental effects of C-Ser when directly mixed with

The use of alkaline activator in alkali-activated materials (AAMs) may pose risk of alkali-silica reaction (ASR), and the variations in the mixture design could have great influence on the performance of AAMs system. In this case, this paper investigated the effects of slag fineness (3000–8000 cm2/g) and water-to-binder (w/b) ratio (0.5–0.8) on ASR behavior of alkali-activated slag (AAS) mortars under

CO2 curing cementitious materials shows promise as a method to both reduce and sequestrate CO2, nonetheless, it results in the formation of a gradient structure in them. In this study, the mechanical behavior, damage mode and inhomogeneity of carbonated cement pastes are investigated, aiming to establish the intrinsic link between their damage and inhomogeneity. The results indicated that carbonated

In recent years, there has been a growing interest in the use of nanomaterials as additives in various industries, including cement production. Among these materials, carbon-based nanomaterials, such as graphene and graphene oxide, have been extensively studied for their potential applications in cementitious materials. However, recent research has shown that boron nitride nanotubes (BNNT) can offer

To promote the application of carbonated recycled concrete powder (CRP), it is vital to thoroughly understand the performance of recycled concrete powder (RP) during the carbonation process. This paper presents an experimental study on the multiscale microstructure evolution of CRP and its chemical reactivity development during gas-solid carbonation. The phase transformation, nanostructure and reactivity

Assessing the permeability of concrete is crucial as it governs the transport of aggressive agents, such as chlorides and carbon dioxide, which are key factors in the degradation mechanisms. Moreover, concrete's permeability constitutes an essential input parameter for durability models. Concrete's permeability can be measured directly (by experimental methods) or indirectly by fitting a transport

This study investigated composite cements with recycled concrete pastes (RCP) and the carbonated analogue, comparing them to Portland and limestone cements. The carbonation curing resulted in a carbonation degree of around 30 %. The presence of supplementary cementitious materials had little impact on the carbonation degree and phase assemblage. Cement pastes consisted of ettringite, calcium carbonate

The construction industry has been facing significant challenges in reducing CO2 emissions. As such, accelerated carbonation has attracted explosive attention in view of its ability to bind CO2 back to construction materials while improving their performance. Water is a decisive factor in carbonation because it bridges the reaction between gaseous CO2 and solid precursors, and three distinct approaches

This research investigated the mechanical performance of Functionally Graded Fiber-Reinforced Concrete (FG-FRC) produced via extrusion with a targeted fiber injection. Flexural toughness was assessed using a modified ASTM C1609, and fracture properties were analyzed through implementation of the two-parameter fracture model. The study introduced an innovative targeted fiber injection technique using

Buildings can be rapidly constructed using 3D printed concrete technology without formwork, garnering increasing attention within the construction industry. The effects of different printing parameters on the splitting tensile strength, shear strength, pore structure, and micromorphology of the interface between 3D printed ECC and post-cast concrete were investigated, including single-layer printing

The massive discharge of copper slag (CS) has led to serious environmental problems. Carbon mineralization, as a treatment method of solid waste, not only achieves carbon sequestration, but also enhances the pozzolanic activity. In this work, a novel exfoliation aqueous carbonation method combining aqueous carbon mineralization and wet grinding was proposed to evaluate the carbon mineralization behavior

The use of seawater sea-sand concrete in marine infrastructure not only offers significant sustainability benefits by minimizing the energy consumption and carbon emissions associated with transportation activities, but also helps mitigate the environmental impact caused by excessive sand mining in riverbeds. The study presented in this paper aims to contribute to this growing area of research by introducing

Ferrochrome slag (FCS) is one of the main by-products generated from the smelting of ferrochrome alloy. Its utilization as aggregate can reduce the mining of natural aggregate and cost of ultra-high performance concrete (UHPC). The morphology of aggregate, maximum size (Dmax) and particle gradation are key factors that affect the properties of concrete. Herein, the morphology of FCS compared to river

This study systematically investigates the influence of ultrafine iron ore tailings (UIOT) on the performance and hydration process of supersulfated cement (SSC) with high phosphogypsum (PG) content. UIOT incorporation retards early-age strength but enhances later-age strength, with a 20 % replacement ratio of granulated blast furnace slag (GBFS) leading to a 52 % increase in 28-day compressive strength

The bond-enhancing mechanisms of nano-silica (NS) deposition, described solely by a pozzolanic reaction, have often overlooked its underlying physicochemical nature. We propose a novel framework to quantify spatial disorder in NS deposition and to analyze its impact on the interfacial bond properties of carbon textiles in cement composite. The framework leverages domain knowledge (the morphological

This study introduces a novel method for incorporating artificial flaws in Engineered Cementitious Composite (ECC) by applying carbon nanotube (CNT) polymer nanocomposite coatings, which has a porous microstructure, to aggregates. In comparison with the control ECC, the implementation of coated aggregates can improve the crack number and the strain capacity of ECC by 268 % and 83.7 %, respectively

Synthetic C-S-H/PCE nanocomposites are outstanding seeding additives to promote the early performances of Portland cement. For an extensive application of the seeding material, it is essential to understand the fundamentals of hydration, microstructure, and early strength of cement with the nanocomposites. In this study, the hydration process and microstructural evolution of cement pastes containing

Increasingly electromagnetic pollution derived from portable electronic devices and communication systems urges the development of electromagnetic waves (EMWs) absorbing cementitious composites. However, it remains a challenge to achieve a balance between excellent mechanical and EMWs absorbing properties of cementitious composites, and it has not been systematically summarized. It is of great significance

Water permeability tests (WPTs) based on Darcy's law ignore inertial effect, yielding biased assessments. This study examines self-healing effects on water resistances of cracked and healed ultra-high performance concretes (UHPCs) with varying steel fiber contents, using a nonlinear WPT based on Forchheimer's law. Permeability coefficients (κv and κi) quantify viscous and inertia energy consumptions

Inhibition effect of traditional corrosion inhibitors is significantly reduced under harsh marine environment. Hence developing corrosion inhibitors with strong adsorption to satisfy efficient corrosion protection for reinforced concrete in harsh marine environment is urgent. By using multiple adsorption sites and abundant internal pores in metal organic frameworks (MOFs), a novel highly efficient

This study investigated the effect of triethanolamine (TEA) on the hydration and carbonation of Class C fly ash (FA) varying its dosages (1 wt% and 5 wt%). From an early age, TEA enhanced the dissolution of calcium and alumina of FA, leading to improved hydration and carbonation. As a result, regardless of curing conditions, the reactivity of merwinite (C3MS2) and the formation of katoite (C3AH6) increased

This investigation demonstrates a pioneering approach for synthesizing highly carbonation-reactive fibrous α-wollastonite (α-CS) binder through crystal transformation activation of natural wollastonite, resulting in negative CO2 emission while achieving superior mechanical properties. The rapid crystal transformation activation from natural CS to α-CS was accomplished at 1200 °C, markedly enhancing

Traditional concrete fulfills the mechanical requirements for marine infrastructures but lacks durability. This study employed nano-engineering techniques to address the durability challenges in marine concrete infrastructures by enhancing the chloride ions penetration resistance of low- and medium-strength concrete to be comparable to that of high-strength concrete without increasing cement dosage

Quantifying the constraint effect of coarse aggregates on mortar shrinkage is essential for predicting the bulk shrinkage of concrete. This study investigated the formation and evolution of tensile strain/stress shells around coarse aggregate in concrete under dry conditions by using digital image correlation and lattice fracture modelling. The average constraint shell thickness and constraint index

Recycling construction solid waste is an immediate need due to the substantial amount of construction waste that occupies valuable land and poses environmental hazards. In response to challenges related to the performance and interfacial transition zone (ITZ) when using recycled aggregate (RA) in concrete, a modified formulation with low calcium phosphate (CaP) content was developed to enhance RA's

Recycled concrete powder (RCP) influences cement paste's rheology, but the mechanisms remain unclear. This paper intends to fill this gap by employing a new method for measuring water absorption, the minimum water requirement method, an organic carbon analyser, and a laser particle size analyser. The cementitious material's water absorption (W), packing density (φm), water reducer adsorption (Qad)

3D-printing could offer substantial benefits to the construction industry including the fabrication of customized/bespoke components, eliminating formwork, and reducing material waste. Despite these advantages, control of the pumpability, extrudability, and buildability of 3D-printed concrete (3DPC) remains challenging. This study demonstrates how the use of fly ash (FA) enables enhanced thermal stiffening

Interest in the use of graphene to enhance the properties of cementitious materials is growing, but major impediments in implementation are the cost of graphene and changes in binder rheology attributable to these nanomaterials. This study explores the influence of novel, cost-effective, environment-friendly, and mass-producible graphene on the rheology and early-age structure development of cementitious

Concrete 3D printing proposes an off-site industrial process allowing to deposit material only where required. However, most mixture design methods struggle to perform, which is why a majority of 3D printing materials display high clinker contents. This study proposes a reproducible methodology for tailor-made 3D printing materials. Applied to a low-clinker quaternary blend, an iterative optimization

While self-consolidating concrete (SCC) has emerged as a highly effective approach for the repair of concrete structures, there have been few investigations regarding the effect of the combination of different fiber and shrinkage-mitigating material types (shrinkage-reducing admixture, SRA; superabsorbent polymer, SAP; and expansive agent, EA) on the flexural behavior of repaired structures. This study

The utilisation of carbonated recycled aggregates in concrete has been increasingly considered as an effective strategy for CO2 sequestration in the built environment and enhancement of concrete sustainability. Following up a pervious review on the role of carbonated recycled concrete aggregates in the mechanical properties of concrete, this paper presents a comprehensive review on the effects of carbonation

Excavated soil from widescale tunneling and excavation can be used in 3D-printed constructions. This research investigates the feasibility of 3D printing using geopolymer stabilized excavated soil (GP-E) containing 42% clay rich in kaolinite minerals. At dosages 0.50–1.5 wt%, sucrose is added to control the hydration and time-dependent rheological properties, enabling adequate open printing time (OPT)

The internal structure of coating mortars often displays considerable variability, posing challenges in analysing and comparing their diverse performance characteristics. Yet, employing advanced characterisation and diagnostic techniques offers a pathway to a deeper comprehension of mortar composition and microstructural traits, thereby establishing crucial performance benchmarks.

This study is aimed at assessing the synergy of the biochar utilization and early age CO2 curing on the mechanical performance, hydration and CO2 uptake in cementitious materials. Three different biochars Bamboo biochar (BBC), Peanut Husk Biochar (PHBC) and Rice Husk Biochar (RHBC) were utilized with dosages up to 5 % by mass of cement and their influence under water curing and early age CO2 curing

In the realm of sustainable construction materials, this study delves into the feasibility of utilizing wood-derived biochar as a partial substitute for sand in mortar. Carbon mineralisation potential of mortar increases due to the presence of biochar. Inclusion of biochar leads to improved thermal performance, manifested through reduced thermal conductivity, and increased specific heat capacity. Water

The high alkalinity, chlorine, and potentially toxic elements (PTEs) content of municipal solid waste incineration fly ash (MSWI FA) hindered its potential application in construction materials. This study proposed the recovery of MSWI FA via wet carbonation and developed a novel sustainable carbonated-MSWI FA-based binder. Experimental results showed that MSWI FA achieved 12 wt% CO2 capture through

The use of argon oxygen decarbonization slag (AODS) is restricted due to its volume unsoundness and low hydration reactivity. In this study, the feasibility of transforming AODS toward a highly reactive mineral admixture with appreciable CO2 sequestration was investigated, the hydration behavior, evolution of the compositions and microstructures of AODS with carbonation time were systematically studied

The interfacial bonding between steel fibers and Ultra-High Performance Concrete (UHPC) matrix is pivotal for the mechanical properties in extreme environments. Herein, a surface nanoengineering approach using the sol-gel method was reported to enhance the resistance of fiber bonding to varying cryogenic and elevated exposures (−170 °C ∼ 200 °C). Additionally, the interfacial bonding and failure of

This study explores the feasibility of NaCl based magnesium phosphate cement (NaCl-MPC) composites as a solid electrolyte for energy storage applications by analyzing the physical, mechanical, hydration and electrochemical properties of composites. The results indicated that the incorporation of NaCl greatly improved the mechanical properties and ionic conductivity of composites, demonstrating enhanced

To enhance the safety and functionality requirements of engineering structures, carbon nanotubes are used to improve the performance of concrete. However, their high cost limits their large-scale application. In this study, industrial multi-walled carbon nanotubes (IMWCNT) were employed to ultra-high performance concrete (UHPC) to achieve a balance between nanomodification and economy. The effects

A ductile oil well cement paste (OWCP) with lower autogenous shrinkage is of paramount importance to the integrity of cement sheath under downhole condition. Taking advantage of multiple experimental tests and a micromechanical model, the hybrid effects of nano-rubber (NR) and carbon nanotubes (CNTs) on the mechanical properties, autogenous shrinkage, hydration behavior and microstructure of OWCP were

Engineered geopolymer composites (EGC) are promising alternatives to highly ductile cement-based composites, whereas effectively balancing the strength and ductility of most developed EGC mixes is challenging. This study systematically evaluated the feasibility of incorporating nano-silica (NS) particles to address the problem of balancing strength and ductility in EGC, aiming to develop EGC with extraordinary

In this study, we explored the potential of microbiologically induced calcite precipitation (MICP) for enhancing the microstructural integrity of waste concrete fines (WCF). Traditionally, ureolytic bacteria, such as Sporosarcina pasteurii, have been widely used in MICP due to their ability to produce calcium carbonate via urea hydrolysis, but this process generates ammonia, raising environmental concerns

Microbial induced concrete corrosion (MICC) is the main deterioration mode of concrete corrosion in concrete wastewater transportation system. Protective coating is one of the commonly used microbial corrosion protection technologies for concrete. In this study, the effects of CuSO4 concentration and pH value of electroless plating solution on the preparation of copper-plated hardened cement paste

Most literature has focused on the effect of shrinkage-reducing admixture (SRA) in shrinkage mitigation resistance of concrete. This study aims to examine the impact of SRA on the efficiency of macro synthetic fibers (MSF) in enhancing the flexural post-cracking behavior of fiber-reinforced super workable concrete (FR-SWC). A comparative analysis of the influence of fiber combinations on the flexural

Conventional alkali-activated slag materials apply strong industrial alkalis with high cost and potential corrosion risk. Alternatively, this study utilized industrial solid waste phosphogypsum, soda residue, and calcium carbide slag to construct a salt-alkali synergistic activated system. A new salt-alkali synergistic activation effect was formed by the SO42− introduced by PG together with the Cl−

Fire is detrimental to skyscrapers. Lightweight high-performance concrete (L-HPC) developed by combining lightweight microspheres and ultra-high-performance concrete binder is promising for future mega infrastructure projects. This study investigates the fire resistance of lightweight high-performance cementitious composites developed using hollow ceramic microspheres (HCMs) and hollow glass microspheres