• Drying shrinkage prediction
• Durability properties
• Environmental evaluation
• Multi-walled carbon nanotubes
• Rice husk ash

• REIG-FETBE-2022/017 UCSI University Research Excellence & Innovation Grant (REIG)
• FRGS/1/2024/TK06/UCSI/02/1 Malaysian Ministry of Higher Education (MOHE) for supporting this work through the Fundamental Research Grant Scheme (FRGS)
• UCSI University Research Excellence & Innovation Grant (REIG)

• FRC
• UHPFRC
• constitutive law
• flexural tests
• uniaxial tensile tests

• 826881 Austrian Research Promotion Agency

• cement toughness
• defoamer
• electrostatic self-assembly
• graphene oxide
• modified nanomaterials
• oil well cement

• microstructure
• orthogonal experiment
• pore characteristic
• steam-cured concrete

• 2022DB027 Xinjiang Production and Construction Corps through its Financial Science and Technology Plan Project

• alkaline exposure
• concrete
• durability
• post-consumer carpet fibers
• recycling

• Hybrid nanoparticle
• biomedical applications
• classifications
• hybrid.
• medical benefits
• polymer lipid hybrid nanoparticle

• Humans
• Nanoparticles/chemistry
• Animals
• Drug Delivery Systems

• carbon nanotubes
• cement
• composites
• compressive strength
• concrete
• functionalization
• mortar

• acid resistance
• alkali–silica reaction
• graphene oxide
• mechanical test
• mortars
• sodium silicate waste

• PID2019-110928RB-C33. Ministerio de Ciencia e Innovación of Spain
• US-1266248 Regional Government of Andalusia

• alkali treatment
• alkali-activated slag
• autogenous shrinkage
• cow dung fibers
• ultrasonication

• 51978171 National Natural Science Foundation of China
• FJHJF-2022-19 Fujian Ocean and Fishery Bureau
• 2021-P-031 Fuzhou Science and Technology Bureau
• GXRC-19045 Minjiang Scholar program of Fujian province, China

• FTIR
• alkali-activated materials
• design of experiments
• shrinkage

• engineering
• materials science

• conductive functionality
• mechanical reinforcement
• physical modification
• steric repelling force

• carbon nanotubes
• cement
• interfacial shear strength
• mechanical properties
• molecular dynamics
• pull-out

• artificial muscle
• crack dispersion
• electrical stimulation
• fishing line
• high performance fiber-reinforced cementitious composites (HPFRCC)
• nylon fiber
• shrinkage
• temperature
• twisted and coiled polymer actuator (TCPA)

• NDT
• acoustic emission
• concrete
• early age damage
• new diagnostic method
• shrinkage

During geothermal energy development, the bottom high-temperature fluid continuously exchanges heat with the upper low-temperature wellbore and the stratum during its rising process. Thermal insulation cement (TIC) can increase the outlet temperature, thus effectively reducing the heat loss of the geothermal fluid and improving energy efficiency. In this study, vitrified microbubbles (VMB) were screened out by conducting an orthogonal test of compressive strength (CS) and thermal conductivity (TC) on three inorganic thermal insulation materials (VMB, expanded perlite (EP), and fly-ash cenosphere (FAC)). Fumed silica (FS) was introduced into the cement with VMBs, as its significant decreasing effect on the TC. Moreover, a cement reinforcing agent (RA) and calcium hydroxide [CH] were added to further improve the CS of TIC at 90 °C. The fresh properties, CS, TC, hydration products, pore-size distribution, and the microstructure of the cement were investigated. As a result, a TIC with a TC of 0.1905 W/(m·K) and CS of 5.85 MPa was developed. The main conclusions are as follows: (1) Increasing the mass fraction of the thermal insulation material (TIM) is an effective method to reduce TC. (2) The CH content was reduced, but the C–S–H gel increased as FS content increased due to the pozzolanic reaction of the FS. (3) As the C–S–H gel is the main product of both the hydration and pozzolanic reactions, the matrix of the cement containing 60% FS and VMBs was mainly composed of gel. (4) The 10% RA improved the cement fluidity and increased the CS of TIC from 3.5 MPa to 5.85 MPa by promoting hydration.

In this paper, eight variables of cement, blast furnace slag, fly ash, water, superplasticizer, coarse aggregate, fine aggregate and flow are used as network input and slump is used as network output to construct a back-propagation (BP) neural network. On this basis, the learning rate, momentum factor, number of hidden nodes and number of iterations are used as hyperparameters to construct 2-layer and 3-layer neural networks respectively. Finally, the response surface method (RSM) is used to optimize the parameters of the network model obtained previously. The results show that the network model with parameters obtained by the response surface method (RSM) has a better coefficient of determination for the test set than the model before optimization, and the optimized model has higher prediction accuracy. At the same time, the model is used to evaluate the influencing factors of each variable on slump. The results show that flow, water, coarse aggregate and fine aggregate are the four main influencing factors, and the maximum influencing factor of flow is 0.875. This also provides a new idea for quickly and effectively adjusting the parameters of the neural network model to improve the prediction accuracy of concrete slump.

• BP neural network
• determination coefficient
• parameter optimization
• response surface method
• root mean square error
• slump

The characteristics of a concrete mix are purely dependent on the hydration of cement that is carried forward by using the water quality used in the mix. Several researchers have focused on incorporating pozzolanic or nanomaterials to improve the hydration mechanisms and impart high strength to concrete. A new technology has been introduced to improve the properties of concrete by magnetic-field-treated water (MFTW). Due to magnetization, water particles become charged and the molecules inside the water cluster decrease from 13 to 5 or 6, which eventually decreases the hardness of water, thus improving the strength of concrete when compared to the use of normal water (NW). In advanced construction techniques and practices, the application of Magnetic Water (MW) plays an important role in boosting physicochemical properties. This research work focused on evaluating the standards of water quality through physiochemical analysis, such as Electrical Conductivity (EC), Viscosity, pH, and Total Dissolved Solids (TDS) with the MW at different exposure periods (60 min (MW60), 45 min (MW45), 30 min (MW30), 15 min (MW15), and instant exposure (MWI)). Experiments were carried out to evaluate the fresh, hardened, and microstructural behavior of concrete made with magnetic water (MW) using a permanent magnet of PERMAG (N407) under a field intensity of 0.9 Tesla. In addition, optical properties such as X-ray Diffraction (XRD) and Ultraviolet (UV) absorption were considered for the MW60 mix to ensure water magnetization. Characterization methods such as Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy (SEM) were employed for NWC and MWC to quantify the hydrated products. From the results, it was observed that the magnetic effect on water characteristics showed significant improvement in the concrete properties with the increase in exposure duration. There were increments of 25.6% and 24.1% in workability and compressive strength, respectively, for the MW60 mix compared to normal water concrete (NWC).

• X-ray diffraction
• compressive strength
• magnetic field
• magnetic water
• workability

• Cement
• Coal bottom ash
• Construction and demolition
• Environmental development
• Olive stone ash
• Palm oil fuel ash
• Replacement
• Rice husk ash
• Sustainable concrete

• Coal
• Coal Ash
• Construction Materials
• Palm Oil
• Recycling

A large amount of stone powder is produced during the production of machine-made sand. This research aims to study the effect of wet-process tuff silt powder (WTSP) dosages (as an alternative sand material to utilize waste stone powder and reduce environmental hazards) on reactive powder concrete’s (RPC) mechanical performance. The physical and chemical properties of WTSP were analyzed as per relevant standards. This study prepared RPC samples with various WTSP content (0%, 6%, 12%, and 18%) to replace quartz sand at the same water–binder ratio (0.14) and allowed the samples to cure for 3 days, 7 days and 28 days prior to unconfined compression testing and flexural testing. Scanning electron microscopy (SEM) and Mercury Intrusion Porosimetry (MIP) testing were also carried out to observe the evolution of macroscopic properties in response to replacing part of quartz sand with the same amount of WTSP. The results show that the developed flexural and unconfined compressive strength (UCS) decreases slowly with a greater dosage of WTSP. However, when the WTSP content is 12% or less, the RPC made with WTSP satisfies the industrial application threshold regarding mechanical properties. For RPC samples containing more than 12% WTSP, the UCS and flexural strength showed a dramatic drop. Thus 12% of WTSP content was deemed the maximum and the corresponding UCS of 104.6 MPa and flexural strength of 12 MPa for 28 days of curing were the optimums. The microscopic characteristics indicate that the addition of WTSP can effectively fill the large pores in the RPC micro-structure, hence reducing the porosity of RPC. Furthermore, the WTSP can react with the cementitious material to form calcium aluminate during the hydration process, further strengthening the interface. The alkaline calcium carbonate in WTSP could improve the interfacial adhesion and make the structure stronger.

• RPC
• mechanical properties
• microstructure
• wet-process tuff silt powder

Concrete is known as the most globally used construction material, but it releases a huge amount of greenhouse gases due to cement production. Recently, Supplementary Cementitious Materials (SCMs) such as fly ash and Ground Granulated Blast Furnace Slag (GGBFS) have been widely used in concrete to reduce the cement content. However, SCMs can alter the mechanical properties and time-dependent behaviors of concrete and the early age mechanical properties of concrete significantly affect the concrete cracking in the engineering field. Therefore, evaluation of the development of the mechanical properties of SCMs-based concrete is vital. In this paper, the time development of mechanical properties of concrete mixes with various fly ash and GGBFS was experimentally investigated. Four different cement replacement levels including 0%, 20%, 30%, and 40% by fly ash and GGBFS as well as ternary binders were considered. Compressive strength, splitting tensile strength, flexural strength, and elastic modulus of concrete were measured until 28 days. Three additional concrete mixes with ternary binders were also cast to investigate the early-age autogenous shrinkage development until 28 days. In addition, prediction models in existing standards were used and compared to experimental results. The comparison results showed that the prediction models overestimated the compressive strength but underestimated the splitting tensile strength development and autogenous shrinkage. As a result, a model capturing the effect of fly ash and GGBFS on the development of compressive and splitting tensile strength is proposed to improve the prediction accuracy for current standards and empirical models.

• GGBFS
• autogenous shrinkage
• concrete
• fly ash
• mechanical properties
• prediction model

• SEM-analysis
• artificial lightweight aggregate
• fly ash–slag mix
• geopolymers
• lightweight geopolymer concretes