Discontinuities in rock mass are the characteristic challenge of rock tunnel engineering projects, which have a vital impact on rock mass exposures' mechanical and hydrological characteristics. There is a growing demand for predicting the fracture maps during tunnel excavation to ensure a smooth tunnel excavation process. The computer vision measurement of fractures in the tunnel surface is a current

The demand for resilient and smart structures has been rapidly increasing in recent decades. With the occurrence of the big data revolution, research on data-driven structural health monitoring (SHM) has gained traction in the civil engineering community. Unsupervised learning, in particular, can be directly employed solely using field-acquired data. However, the majority of unsupervised learning SHM

This study experimentally evaluated the seismic performance of beam-column joints with different compressive strengths. A total of three exterior beam-column joints were fabricated and tested under reversed cyclic loading. The primary test parameter was the ratio of the concrete compressive strengths of the column and beam. The crack patterns and failure mechanisms, load-displacement relationships

Current early stage assessment methods for deep excavation induced structural damage have large uncertainty due to modeling idealizations (simplification in analyses) and ignorance (incompleteness of information). This paper implements an elastoplastic two-stage solution of soil-structure-interaction to predict building response to adjacent deep excavations with braced supports. This soil-structure-interaction

The study aims to examine the feasibility of recycling autoclaved aerated concrete waste (AACW) on a large scale to prepare sustainable mortar without large mechanical strength reduction. To this end, recycled AACW was utilized as fine aggregate to partially replace natural river sand in mortar with various replacement levels and particle sizes. The physical properties and mechanical strength of prepared

Microbial induced calcium carbonate precipitation technology was proposed as a novel and environmentally friendly approach to strengthen the surface layer of cement-based materials in this study. The effects of microbial additives on the content of Ca(OH)2 and CaCO3 and the porosity at different depths of surface layer were studied. The relative efflorescence rate of cement mortar samples mixed microbial

The building industry is a large contributor to greenhouse gas (GHG) emissions and a vast consumer of natural resources. It is estimated that, in the next 40 years, around 415?Gt of CO2 will be released as a result of global construction activities. Therefore, improvements in construction technologies are essential to reduce GHG emissions and thereby attain national and international goals to mitigate

CO2 mineralization using alkaline waste materials and by-products is a promising technology to reduce CO2 emissions. This work investigates the impact of alkali sulfates on the carbonation process. Detailed investigations of the carbonation reaction show that the sulfates are important phases impacting the mineralization. Alkalis alone accelerate the kinetics and change the morphology of the precipitated

This paper presents the material and process-related research that underpinned the realisation of the Parque de Castilla Footbridge in Madrid in 2016, going from the laboratory to the industrial scale. The fibre-reinforced cement-based composite was first developed and tested in a small-scale particle bed printer focusing on evaluating the influence of the material and process on the mechanical response

Antimicrobial alkali-activated slag (AAS) with biocidal effectiveness is a promising cementitious binder for concrete infrastructure threatened by microbially induced concrete corrosion (MICC). In this work, the influence of sodium benzoate on the chemical reaction, phase assemblage, microstructure, and nanostructure of AAS was studied, with a particular focus on the potential in-situ formation of

In this work, four types of diatomite-silica aerogel incorporated composites (DSAC) with various diatomite-silica aerogel mass ratios of 1:1, 2:1, 3:1 and 4:1 were prepared by the negative pressure adsorption method. Subsequently, four groups of DSAC with different mass ratios of 0.1, 0.15, 0.2 and 0.25 were added into the cement-based matrix. Observing the morphology and microstructure of DSAC with

Although lithium nitrate is a commonly used method to mitigate the alkali-silica reaction (ASR) in conventional Portland cement systems, such kind of research has not been conducted on alkali-activated material (AAM) systems. In this study, the mitigation effect of lithium nitrate on the ASR in an AAM system was investigated for the first time. The results indicate that lithium nitrate is not effective

As important urban transportation hubs, the subway stations with a massive flow of people require more evacuation exits. This study combined the exit choice model and the social force model with pedestrian classification. Three influencing factors were discussed in calculating the utility value: pedestrian density, distance from pedestrian to exits, and exit width. The effects of distance and density

Today, depending on the increasing population and technological developments, household appliances have significantly increased. This situation causes an ever-increasing energy demand, especially in modern societies. However, efficient energy use is also critical due to limited energy resources. With the Non-intrusive load monitoring methods, the usage of home appliances can be controlled, and behaviours

Air-conditioning relies on electricity that isn’t ubiquitous while policies encourage passive alternatives —yet cooling really should respond to occupants’ distress. Here I show where passive measures have been sufficient for comfort and identify local predilections for rebalancing demand between heating and cooling —apportioned by population neighboring meteorological stations. Access to air-conditioned

Engineered cementitious composite (ECC) is a kind of high performance cement-based composite materials with strain hardening and multiple cracking behaviour. Replacing concrete with ECC in the beam-to-column connection with ring beam may effectively improve the load-carrying capacity and ductility, as well as prevent cracks and solve durability problems caused by the brittleness of concrete. In this

The revolution towards Industry 4.0 in the AECO Industry has taken Building Information Modelling (BIM) as one of its central points. BIM abilities for automatization, interoperability and sustainability play a key role in this change. In this paper, a literature review about BIM adoption for the structural project is presented. The aim of the presented review is to clearly establish the current state

Human-robot collaboration has gained popularity in various construction applications. The key to a successful human-robot collaboration at the same construction workplace is the delicate algorithm for predicting human motions to strengthen the robot's situational awareness, i.e., robot-human awareness. Most existing approaches have focused on predicting human motions based on repetitive patterns of

The integration and processing of monitoring data in Historical Building Information Modeling (HBIM) can aid the design, restoration, and maintenance activities of historic buildings through the conscious assessment and potential improvement of their performance. In this regard, this paper presents a new methodology for performing structural performance and human-centric environmental comfort monitoring

Close-proximity tunnellng seriously threatens the safety of existing tunnels and, therefore, leads a pressing need of enhancing our understanding of the role and mechanical properties of liner joints in tunnel construction. This study conducted an investigation into the moment-joint opening and load–displacement relationships of the liner joints under the effect of shield approaching, reaching, and

Introduction Disability glare from lighting systems is considered to be one of the main causes of accidents in road tunnels. The present study aimed to investigate the estimated method of disability glare, the experimental method of visibility level, overall uniformity, and longitudinal uniformity of the tunnel lighting system during driving inside very long road tunnels. Methods The disability glare

This research was performed to investigate the NaOH pre-treatment, chemical additives, and their combined effects on the properties of wood cement panels produced with sunflower stems. The experimental panels were produced with a target density of 1200?kg/m3, a wood/cement ratio of 1:3 and a dimension of 500?mm?×?500?mm x 10?mm using the treated/untreated sunflower stem particles as a partial replacement

The design limit states form the basis of current structural fire design approaches. These design practices overlook the post-fire resilience and repairability of the structure. Consequently, a minor fire might lead to an irreparable structure and a need of demolishing it. We propose a framework to evaluate during the design phase the anticipated repair cost for a structure in case of a fire event

In this paper, ultra-high strength bars (UHSB) was innovatively applied to the high-strength recycled aggregate concrete (RAC) shear walls to achieve resilient performance. In order to explore the resilient and seismic performance of the shear wall, five specimens with shear span ratio of 2.2 were tested under cyclic loading. The variables also included the type of longitudinal reinforcement in boundary

The energy consumption supervision is required for each smart home to ensure the highest power quality and to enhance the stability of the whole grid. In this paper, a various-goal energy management system is proposed to arrive at a compromise solution for smoothing the smart home power profile, reducing the electricity bill (E.B) and obtaining a free charging of Plug-in Electric Vehicles (PEVs) from

As construction is labor intensive, improvement in labor productivity is essential for achieving better project performance. Activity analysis, a widely adopted approach to improve labor productivity, measures the time spent on specific activities and can identify the root causes of low productivity. The use of automated action recognition using machine learning-based classification based on data (e

Multi-functional kinetic facades have great potential to adapt to the environment, reduce building energy consumption, regulate shading and natural ventilation, and improve human thermal and visual comfort. However, due to their complex nature, kinetic facades systems are often associated with highly onerous time-consuming design and fabrication processes, which significantly limit their diffusion

For intelligent risk prediction and optimization in the shield tunnel excavation under uncertainty, this paper proposes a data-driven decision support framework based on the integration of deep neural network and gradient descent technique (DNN-GDO). More specifically, the DNN architecture for modeling non-linear relationships between influential factors and potential risk is superior in concurrently

This study aims to quantify the characteristic compressive strength of concrete prepared with waste foundry sand up to 50% in two manners. The first one is based on the experimental way and another one is through a probabilistic/statistical manner. 100 numbers of cube samples were formed and tested to find the optimum composition based on the maximum compressive strength. The maximum strength achieved

Considering the energy demand (ED) of 2.9×1010 and of 2.9×1010 MWh in the period between 2010 and 2020, China is one of the largest energy consumers when the world total ED in this period was equal to 14×1010 and 15.46×1010 MWh. By concentrating on the building sector, paraffin-based phase change materials (PCMs) are used to reduce ED associated with air conditioning. For building walls with a thermal

This study evaluated the compressive strength performance and microstructure of binary blast furnace slag-sewage sludge ash (BFS-SSA) alkali-activated mortars, in which rice husk ash (RHA) was dissolved in NaOH solution to replace commercial sodium silicate. The dissolution of RHA, performed in a thermal bottle with NaOH solution, enhanced the compressive strength of the alkali-activated mortars based

In local exhaust ventilation systems, external turbulence from e.g. human movements can affect the capture efficiency of the system considerably. In this study, experimental and numerical (CFD) approaches were utilized to evaluate the effect of human movement on the capture efficiency of a local exhaust ventilation system with an exterior circular hood. Human movements were simulated by back-and-forth

In this study, a novel connection consisting of high-strength bolts and connecting steel plates used for horizontal joints of fully precast RC wall panel structures was proposed. Four precast wall panels were jointed using the novel connection and tested under reversed cyclic load to investigate the seismic performance. Several variables, such as the spacing of the stirrups, the diameter of the bolts

Research has shown that reaction kinetics and physical transformation during alkali-activation of aluminosilicate materials are sensitive to both the compositions of raw precursors and the alkaline solution. Methods that allow for early observations relating to reaction kinetics, and that capture early-age physicochemical transformations with sufficient accuracy, can assist design engineers in bringing

This research investigates the effect of the physicochemical characteristics of five cognate fly ashes on the mechanical properties of Class F fly ash-based geopolymers synthesized with the same mix proportion and cured at ambient conditions. X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and low-field nuclear magnetic resonance were conducted to create the quantitative

Composite cements belonging to the CaO–Al2O3–ZrO2 (C-A-Z) and CaO–SrO–Al2O3–ZrO2 (C–Sr-A-Z) systems were evaluated as alternatives to calcium aluminate cements (CACs) for use in the refractory castables technology. The mineralogical phases in the as-synthesized C-A-Z and C–Sr-A-Z clinkers confirmed by XRD and SEM-EDS were CaAl2O4, Ca7ZrAl6O18 and CaZrO3 or (Ca,Sr)Al2O4, (Ca,Sr)Al4O7 and (Ca,Sr)ZrO3

Geopolymers have been a frequently studied topic during the last decades due to waste materials utilization, low energy demands, and low carbon dioxide emissions related to their production, which makes them very attractive within the current environmental trends. However, the original idea to use them as a concrete replacement showed to be unattainable in the nearest future, so other alternatives

Due to high operation cost of dedicated inspection vehicles, conventional pavement management systems (PMS) suffer from limited data quantity collected from periodic inspections. However, increasing market penetration of connected autonomous vehicles (CAVs) offers opportunities to monitor pavement conditions more frequently through sensors, including vision cameras and accelerometers, originally installed

Monitoring unsafe operations of construction machines is important for reducing accidents on sites. To automate safety monitoring, this paper studies pose estimation of construction machines, which describes their motions in 3D space. Inertial Measurement Unit (IMU) is considered accurate, cost-saving and user-friendly for estimating the pose of machines. Nevertheless, the complexity and instability

To advance the research on recycled concrete (RC), recycled coarse aggregate (RCA), recycled fine aggregate (RFA) and recycled powder (RP) were used in preparing fully recycled aggregate concrete (FRAC), which lead to more comprehensive usage in the recycling of concrete waste. Recycled aggregates were studied as types of aggregate combinations instead of partial substitutes, and four aggregate combinations

This paper introduces a novel approach to integrate orientation-dependent spectral properties of daylight in urban planning. These spectral characteristics of light at fa?ades are represented in spectral daylight potential diagrams (SDPDs). The applicability of SDPDs is subsequently discussed in the context of non-image forming (NIF) effects, comparing the NIF effectiveness of skylight at fa?ades—represented

Moisture-related issues in buildings can accelerate the decay of building materials and increase occurrence of mould, resulting in significant economic and health implications. Transient hygrothermal risks assessment proved to be the most reliable approach, yet its application at early design stages is impeded by the high number of assumptions, input and skills required to be robustly applied. Climate-based

In this study, a novel hybrid method for modeling the unconstrained melting of phase change material (PCM) in hot water tanks was proposed. This method analytically calculates solid PCM settling velocities and prescribes them by Darcy terms of numerical models. Its main advantage is that the settling of solid PCM during melting processes is considered without reconstructing solid PCM surfaces and coupling

Extensive transformations of large housing estates in postsocialist cities have been the subject of many studies. However, the effects of transformations resulting from urban densification, upon local microclimate, have not been fully determined. This paper addresses this issue by investigating the implications that vertical extension of residential buildings had on microclimatic parameters of thermal

This work presents an experimental study of the dynamic performance of a CO2 water-to-water heat pump in a domestic hot water production system. A facility was developed and used to characterize the time evolution of the COP of this heat pump, the heating and stratification processes of the hot-water storage tank, and the global COP of the system. Results showed that, when heating the water storage

Air entraining agent (AEA) is often used to improve the freeze-thaw (F-T) resistance of concrete, but with the deterioration of compressive strength. In this paper, the combination of AEA and superabsorbent polymer (SAP) was used to improve the F-T resistance of mortar without sacrificing its compressive strength. The mass loss and relative dynamic elastic modulus were measured after the rapid F-T

A recent regulation in Korea allows the rehabilitation of aging apartment buildings, with vertical extensions up to three floors. To satisfy the increased flexural strength requirement, a method that places vertical reinforcements and re-casts concrete after crushing the boundary elements is proposed. In this study evaluates the flexural performance of shear walls to which the boundary element retrofit

The building sector consumes a significant amount of energy and produces polluting gas emissions. Therefore, many countries have adopted regulations for energy efficiency. In Colombia, Resolution 0549 of 2015 (R0549-2015) has promoted energy efficiency in buildings based on the integration of measures. However, the measures recommended for residential buildings in the absence of air conditioning may

Accidental loading coming from either natural or anthropic hazards can have serious consequences on civil engineering structures capacity and can lead to progressive collapse (PC). In the case of frame buildings, PC is a subject of interest to assess the residual risk of exposure to death for people inside. PC analysis on large structures is rather performed from a numerical point of view. Experimental

In this paper, full-scaled precast concrete shear walls (PCSWs) with spiral-confined lap connections were tested under low reversed cyclic loading tests with axial compression ratios of 0.12 and 0.24. Both one-row and two-row connections were considered in the test program. The spirals in the connections were used to provide additional confinement and to shorten the lap length (a reduced lap length

A novel reinforced concrete hollow-core precast shear wall (HCPSW), including a precast hollow-core wall panel and cast-in-situ boundary elements is proposed in this study with two anti-seismic defence lines. To analyse the seismic behaviour of this wall, six full-scale specimens were tested under cyclic loading, including two types of HCPSWs with different reinforcements in the boundary elements and