Benny Suryanto

Heriot-Watt University · Institute for Infrastructure and Environment

A number of sophisticated techniques, such as NMR imaging and γ-ray attenuation, have now been used to study moisture transport in porous construction materials. This paper presents initial developments in the application of discretized, electrical conductivity measurements as a relatively simple technique to monitor water movement within cover-zon...

The performance of CEM I, CEM III/A and CEM II/B-V reinforced concrete slabs which have been exposed to a marine environment for 18 years is presented. Performance is assessed in terms of porosity, degree of saturation, chloride concentration and electrical resistivity gradients evaluated through the surface ∼150 mm; the condition of the embedded s...

The electrical properties of porous systems are intimately linked to mass transport and flow processes such as diffusion and permeability and offer a simple testing methodology for assessing those properties which are responsible for the durability and long-term performance of construction materials. In the current study, electrical impedance spect...

The influence of ongoing cement hydration and multiple micro-crack formation on the electrical impedance of an engineered cementitious composite (ECC) is presented. Impedance measurements are obtained over the frequency range 20Hz-1MHz and displayed in Nyquist format; in addition, the permittivity and conductivity were de-embedded from the measured...

This paper presents the results of forensic assessments on reinforced concrete half-joint beams tested within the literature through the application of nonlinear finite element analyses. The software package ATENA Science was utilised, in which critical evaluations were conducted into the accuracy of the software in predicting the response of reinf...

This paper presents the finite element modelling of shear-critical reinforced concrete beams strengthened with U-wrapped CFRP fabrics using ATENA. Fracture-plastic constitutive models, implemented in the context of smeared crack and crush-band approach, were employed to represent the nonlinear behaviours of concrete. CFRP U-wraps were modelled as s...

The adoption of the capacity design principle in modern codes of practice allows for multi-storey frame structures to exhibit ductile behaviour in a major earthquake without collapsing. Whilst the risk of shear failure in regions of large inelastic deformation can be largely reduced, the detailing requirements in capacity design often leads to rein...

Advanced computational modeling for the nonlinear analysis of reinforced concrete shear walls is presented. To this end, thirteen shear walls, with height-to-width ratios of 1.0 and 2.0, were analyzed and compared with the experimental data reported by Lefas and co-workers in 1990. These ratios were carefully chosen to enable the structural assessm...

In the absence of resources of calcitic aggregates this work aimed to confirm the suitability of Scottish aggregates in NHL mortar. Strength, sorptivity, porosity and carbonation of mortars made with one siliceous and one felsic (granitic) aggregate have been studied. The results suggest that there are no technical barriers to their use and that en...

This paper presents a case study into the application of nonlinear finite element for the analysis of interior and exterior beam-column joints under reversed cyclic loading. Three beam-column joints, with different reinforcement configurations and test conditions, were considered to assess the accuracy of the currently available constitutive models...

The design for durability and performance-based standards and specifications for reinforced concrete infrastructure, is limited by the lack of rapid, science-based test methods for characterizing the deterioration resistance of concrete. In this paper, this issue is addressed though the application of two-point electrical impedance measurements tak...

To decarbonise the current construction sector and meet the global net-zero target, there is a pressing need to develop an environmentally friendly alternative to Portland cement concrete. Alkali activated and geopolymer concrete have much to offer in this regard. At present, however, there is limited study on the behaviours of alkali activated str...

Joint and plastic hinge regions of a ductile frame structure must be carefully detailed to ensure that the required ductility could be provided as intended, particularly when a high level of ductility is aimed for. However, the stringent detailing requirements for ductility often result in densely spaced transverse reinforcement which adds to const...

Recycled coarse aggregate from construction demolition waste offers a promising and sustainable solution to overcome challenges facing the construction industry, in relation to the increasing landfill areas, decreasing natural aggregate reserves, and increasing environmental impact of concrete production. Previous studies have shown that recycled a...

This paper presents the application of a smeared fixed crack approach for nonlinear finite element analysis of shear-critical reinforced concrete beams. The experimental data was adopted from tests undertaken on twelve reinforced concrete beams by Bresler and Scordelis in 1963, and from duplicate tests undertaken by Vecchio and Shim in 2004. To thi...

Integrated non-destructive testing (NDT) method consisting of acoustic emission (AE) and digital image correlation (DIC) was used to monitor and evaluate the load behaviour of shear-critical reinforced concrete beams subjected to corrosion. Measurement data in the forms of mechanical load, deflection, surface strain and AE signals were processed an...

This paper investigates the influence of varying the spacing of shear reinforcement on the response of six geometrically identical reinforced concrete beams. Each beam was designed with differing longitudinal and transverse reinforcement configurations to provide improved understanding of the importance of providing sufficient shear reinforcement f...

The electrical impedance of an engineered cementitious composite was measured over the temperature range 7-60°c and data are presented over the frequency range 20Hz-1MHz. The work has highlighted that the resistive and reactive components of the complex impedance both displayed an inverse relationship with temperature. When presented in an Arrheniu...

This paper presents the application of three-dimensional nonlinear finite element analysis in studying the complex behaviour of reinforced concrete beam-column joints under reversed cyclic loading. Three different joint types were considered: an interior, an exterior, and a corner joint, each representing typical joint configurations in general mom...

The piezo-resistive response of a relatively mature engineered cementitious composite (ECC) under tensile straining is investigated and compared with previous studies. In this work, tensile tests were performed on four dog-bone shaped ECC samples and during the loading process, electrical impedance measurements were undertaken over the frequency ra...

A report summarising a 2018 Research Award-winning project. The project developed recommendations for the casting position factor used in the determination of basic bond strength of reinforcement in EC2. This project was a collaboration between Dr Benny Suryanto, Dr John Cairns and Martin Aitken of Heriot-Watt University, and the MPA The Concrete...

The four-point flexural test is now making headway as an alternative laboratory investigative technique for determining the tensile properties of Engineered Cementitious Composite (ECC) to the more traditional, direct/uniaxial tensile test. As the fundamental mechanics of ECC specimens tested in four-point flexure are well understood, it is possibl...

The protective qualities of the concrete cover-zone and the condition of the embedded steel (active/passive) surface were studied using reinforced concrete slabs subjected to intermittent wetting/drying. The cementitious binders used within the experimental programme comprised plain Portland cement (CEM I) and Portland cement partially replaced wit...

This paper presents the application of a low-cost digital image correlation (DIC) system for automated crack mapping. The system employed makes use of a conventional digital camera, a remote image recording controller, and an open-source digital image correlation MATLAB software Ncorr. To showcase the potential of the proposed system, two case stud...

The influence of freezing and thawing on the complex electrical impedance of Portland cement mortars is presented with measurements obtained over the bandwidth 20 Hz–1 MHz. Samples were exposed to a cyclic temperature regime within the range −70 °C to +20 °C. In addition to Nyquist plots, the bulk conductivity and permittivity were de-embedded from...

This paper presents the application of discretised, electrical conductivity measurements as a relatively simple technique to monitor both the temporal and spatial moisture profiles of a range of mortar mixes, with and without supplementary cementitious materials. To this end, the mixes were conditioned under two curing regimes representing poor and...

The durability of cement-based materials depends primarily on the environmental exposure conditions and micro-porous nature of the cementitious binder. In this paper, electrical impedance spectroscopy is exploited to study pore structure evolution in fly-ash mortars. To this end, mortar samples were exposed to a cyclic temperature regime over the t...

Automated crack mapping is employed to study the mechanism of shear fatigue in three reinforced concrete beams subjected to monotonic, stationary-pulsating and step-wise moving loads. The longitudinal strain profiles obtained from the crack mapping are used to assess the evolving damage and internal mechanisms of resistance during the load cycles....

The ambient environment has a considerable influence on the permeation properties of the near-surface zone of exposed concrete (i.e. the cover zone). Monitoring the mass transport and flow processes and properties within this region is crucial in evaluating the long-term performance of concrete for a particular exposure condition. This paper presen...

An end-to-end (two-point) electrical measurement technique is traditionally employed in evaluating the bulk resistivity of hardened cementitious materials. This testing methodology is critically evaluated by studying the electrical impedance of an engineered cementitious composite (ECC), using cuboidal specimens with four different dimensions viz....

The mechanical and a.c. electrical properties of a new varietal of engineered cementitious composite (ECC) incorporating conductive inclusions are presented. Electrical measurements were undertaken over a wide frequency range while curing and when under uniaxial tensile loading to study the influence of ongoing hydration and multiple microcrack for...

Wet scanning electron microscopy (WetSEM) and electrical impedance measurements have been employed to study the physico-chemical processes during the early hydration of Portland cement. The WetSEM study employed the Quantomix WetSEM capsule, allowing examination of the morphology of hydrating cement directly in situ via 36 semi-electron-transparent...

A novel technique for enhancing the out-of-plane behaviour of masonry infill walls is proposed herein. The technique involves the use of a thin layer of engineered cementitious composite (ECC) which is fully or partially bonded onto the face of masonry walls. To investigate the feasibility of this technique, the present research focuses on studying...

A low-cost digital image correlation system is used to visualize the formation and propagation of concrete cracking in a reinforced concrete beam. The system employed comprises an ordinary digital camera, a remote image recording controller (a smartphone) and a freely-available, open-source image correlation software package Ncorr. In this paper, t...

A procedure to predict the flexural response of an Engineered Cementitious Composite (ECC) prismatic beam specimen subjected to four-point bending and its implementation into an Excel spreadsheet are described. It utilises the layered sectional analysis approach and nonlinear ECC constitutive models, allowing for the calculation of the moment-curva...

https://www.j-platpat.inpit.go.jp/web/PU/JPB_6214393/B4ACE40DE1B29334A406651C386A29F9 PROBLEM TO BE SOLVED: To provide a high performance fiber reinforced cementitious composite (HPFRCC) superior shear resistance after cracking while keeping the tensile deformation capacity typical for HPFRCC. SOLUTION: The high performance fiber reinforced cement...

The mechanical and electrical properties of an engineered cementitious composite (ECC) while under tensile loading are presented. Direct tensile tests were conducted on dog-bone shaped ECC samples, with simultaneous mechanical and electrical measurements taken during the loading process. Regarding electrical property measurements, these were record...

The application of electrical property measurements for assessing the permeation properties of Engineered Cementitious Composite (ECC) is demonstrated. To this end, a multi-electrode, two-point sensor was embedded within the surface region of two ECC specimens, with one being reinforced with the standard polyvinyl alcohol fibers and the other with...

Three reinforced concrete beams, one with no shear reinforcement and two others with shear reinforcement ratios of 0.4% and 1.1%, were tested to investigate the influence of stirrup spacing on the mode of failure, overall strength and ductility. The results show that the beam reinforced with closely-spaced shear reinforcement failed in a ductile ma...

The electrical properties of Portland cement, and cements containing supplementary cementitious materials (SCM), were obtained over the frequency range 1 kHz-10 MHz during the initial 24 h after gauging with water. The response was measured in terms of conductivity and permittivity with both parameters exhibiting significant temporal changes during...

This paper investigates the feasibility of imaging the movement of water into partially saturated concrete using electrical resistance tomography (ERT). With this technique, the spatial distribution of electrical resistance within the concrete sample was acquired from 4-point electrical measurements obtained on its surface. As the ingress of water...

Satisfactory guidelines for ensuring adequate reinforced concrete durability can only be developed by monitoring concrete performance under a range of field exposure conditions over an extended period of time. Only then can there be a move from prescriptive durability specifications (minimum grade, maximum water-binder ratio, and minimum cement con...

The stiffness differences between aggregate and mortar matrix in concrete create stress concentration at their interface transition zones. Studies on 100mm cubes with different volume and shape of inclusions, resembling aggregate particles within the concrete, suggested that it is always in this transition zone that cracks initiate. Further detaile...

The framework of a practical test method that can be used to provide indirect assessment of the tensile properties of ECC is presented. Particular emphasis is placed on providing the underlying concept, modelling strategy and constitutive relations underpinning the proposed framework. An analysis case study, examining the effect of tensile stress-s...

Electrochemical impedance spectroscopy is used to obtain the electrical properties of fly-ash over the frequency range 100Hz-10 MHz. A range of presentation formalisms are exploited to characterize and assess this material in terms of its unburnt carbon content and pozzolanic reactivity. Fly-ash from a number of power stations within the UK, which...

Indigenous natural Scottish aggregates are currently underutilised for conservation mortars when set within a context of total volume of aggregate extraction. Their geological variability is considerable but they can be broadly characterised by region and predominantly include granitic and siliceous forms. These materials have been associated with...

Environmental Scanning Electron Microscopy (ESEM) is used to study the origin of micro-crack healing in an Engineered Cementitious Composite (ECC). ESEM images were acquired from ECC specimens cut from precracked, dog-bone samples which then subjected to submerged curing followed by exposure to the natural environment. The mineralogical and chemica...

In establishing the reliability of performance-related design methods for concrete – which are relevant for resistance against chloride-induced corrosion - long-term experience of local materials and practices and detailed knowledge of the ambient and local micro-climate are critical. Furthermore, in the development of analytical models for perform...

Alternating current (a.c.) electrical property measurements are presented on an Engineered Cementitious Composite (ECC) reinforced with a hybrid mix of polyvinyl alcohol fibers (fixed dosage) and straight steel fibers of varying dosages (0.15–1.0% by volume), with the aim at elucidating the influence of conductive inclusions on the nature of conduc...

This study investigates the accuracy of Response-2000 in predicting the response of shear-critical reinforced concrete beams. The experimental data selected was that obtained by Vecchio and Shim in 2004 on twelve reinforced concrete beams which sought to replicate beams originally tested by Bresler and Scordelis in the early 1960s. This study also...

The self-healing and self-sensing performances of Engineered Cementitious Composite (ECC) mixtures developed recently at Heriot-Watt University are presented. In the first series of experiments, fifteen dog-bone shaped ECC samples were preloaded to known strains and then left to heal outdoors under a natural environment. Ultrasonic pulse velocity m...

The performance of an Engineered Cementitious Composite (ECC) to self-heal micro-cracks under a controlled laboratory environment is presented. Ten dog-bone shaped samples were prepared; five of them were preloaded to known strains and then left to heal in water in a temperature-controlled laboratory. Ultrasonic pulse velocity (UPV) measurements we...

Ac impedance spectroscopy measurements are used to critically examine the end-to-end (two-point) testing technique employed in evaluating the bulk electrical resistivity of concrete. In particular, this paper focusses on the interfacial contact region between the electrode and specimen and the influence of contacting medium and measurement frequenc...

The self-healing performance of an engineered cementitious composite (ECC) exposed to the natural environment is presented. Fifteen dog-bone shaped ECC samples were preloaded after 14 d of curing and then placed outside in an open area at Heriot-Watt University (Edinburgh campus). Ultrasonic pulse velocity measurements were used to determine the ra...

Flexural bond strength is an important performance characteristic of masonry structures yet there is no guidance for lime-mortared stonework in design codes of practice. This study investigates the bond strength of natural hydraulic lime (NHL) and natural cement mortared sandstone masonry. To this end, the flexural bond strength of masonry couplets...

This paper describes a method for estimating creep deformations of PVA-ECC under high stress levels from short-term tests. To obtain necessary data, a series of accelerated bending and compression creep tests under a sequence of increasing loads were carried out. Of particular interest was to study the evolution of plasticity and damage under varyi...

This paper describes the development of Engineered Cementitious Composite (ECC) in the UK and presentsthe results of preliminary investigations into the fresh and mechanical properties of the composite. To produce the ECC base matrix, locally available fine silica sand and two different fly-ashes were used: EN 450 and Superpozz. The effects of two...

This paper investigates the causes of excessive long-term deflection of PC bridge viaducts by using 3D integrated material-structural analyses to take into account the coupled chemo-physics at various scales from the molecular size of water to the structural members. The excessive deflection observed at site is found to be rooted in the deformation...

This paper investigates the post-cracking behavior of steel fiber rein-forced concrete (SFRC) panels from an analysis perspective based on a smeared, fixed crack approach. The analysis results show that the addition of hooked steel fibers improves the average tensile stress of the concrete and, when added beyond 1% by volume, limits the amount of c...

The evolution of plasticity and fracture under constant, but different stress levels is investigated to study the time-dependent deformations of PVA-ECC under high-stress levels. The elastic deformation in cracked ECC is found to be a good indicator that reflects the rate of plasticity and fracturing. Creep rupture in tension and compression is pre...

Test results of 20 Engineered Cementitious Composite (ECC) plates under 4-point bending are reported. 13 plates were pre-cracked to allow rotation of the principal stress directions, in order to permit the study of shear and tensile stress transfer at multiple cracks. Coarse aggregates were investigated as a possible means to improve shear-transfer...

This paper describes the results of fatigue tests on three shear ECC beams without web reinforcement. Shear fatigue is found to be more severe than bending fatigue, with fatigue life of approximately one to two orders lower. While the crack surface of control beam tested in static are rough and hairy, those tested in fatigue are all smooth. The dam...

This paper focuses on the numerical modeling of high-performance fiber-reinforced cementitious composites (HPFRCCs), specifically polyvinyl alcohol engineered cement composites (PVA-ECCs) in the context of a space-averaged, fixed-crack approach. Compression, tension, and shear models are proposed. The compression and tension models include internal...

This paper presents the verification of analytical modeling for reinforced Engineered Cementitious Composite (R/ECC) in the context of a smeared, fixed crack approach. Verification is provided through the analysis of six R/ECC panels subjected to pure shear. The results demonstrate that the proposed models are capable of replicating various respons...

An experimental program was conducted to investigate the effects of simultaneous opening-sliding of multiple cracks on the behavior of high-performance fiber-reinforced cementitious composites (HPFRCCs). For this purpose, 12 HPFRCC plates were tested in bending and under two constitutive principal stress directions. To facilitate reorientation of t...

This paper describes an attempt to predict the response of shear-critical ECC members that exhibit strong anisotropic stress and strain fields. The ECC members investigated include pre-cracked ECC plates under stress field rotation, orthogonally-reinforced ECC (R/ECC) panel under pure shear, and shear-critical R/ECC beams under reversed cyclic load...

This paper presents a rational shear transfer model for high-strength steel fiber-reinforced concrete (HSSFRC). The model inherently considers shear transfer across smooth cracks, bridged by stiff steel fibers, and the resulting crack slip. When implemented into a nonlinear FE algorithm, the model is shown to perform well in simulating the response...

An endeavor to improve crack-shear interface of HPFRCC was made by adding coarse aggregate to a given HPFRCC mixture. To reveal its effectiveness, four-point bending tests were performed on initially sound and pre-cracked plates all made of original and modified mixtures with coarse aggregate. It was found that a proper amount of aggregate could wo...

An experimental program is undertaken to investigate the influence of damage on cracking behavior of Ductile Fiber Reinforced Cementitious Composite (DFRCC) plates under four-point bending test. The DFRCCs tested herein were the Engineered Cementitious Composite (ECC) and Ductal. The damage was of flexural cracking with different levels and orienta...

This paper describes an experimental program to assess the cracking characteristic of High Performance Fiber Reinforced Cementitious Composite (HPFRCC) after damage. Four-point bending tests were conducted on pre-damaged HPFRCC plates having different initial damage levels and orientations. The result showed three unique cracking characteristics: a...