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The inclusion of pozzolans like pulverised fuel ash (PFA), silica fume (SF) and metakaolin (MK) enhances the properties of concrete both in fresh and hardened states. In the case of high performance concrete (HPC), their role in enhancing the workability, strength and durability is extremely significant. However HPC has been observed to be more vulnerable than normal strength concrete when exposed to elevated temperatures. This paper presents an overview and discusses the strength and durability performance of high‐performance pozzolanic concretes incorporating PFA, SF, and MK subjected to elevated temperatures. Various researchers have demonstrated that addition of silica fume causes HPC to perform poorly when subjected to elevated temperatures. Higher loss of strength and spalling risks are also associated with it. Addition of PFA and MK has been found to improve the fire performance of HPC both in terms of residual strength and durability.

This paper presents an overview and discusses the applications of fibre reinforced polymer (FRP) bars as reinforcement in civil engineering structures. Following a discussion of the science underpinning their use, selected case studies where FRP reinforcement has been used are presented. The use of FRP reinforcement is rapidly gaining pace and may replace the traditional steel due to its enhanced properties and cost‐effectiveness. In addition, FRP reinforcement offers an effective solution to the problem of steel durability in aggressive environments and where the magnetic or electrical properties of steel are undesirable.

Presents an overview and discusses the applications of fibre reinforced polymer (FRP) sheets and plates in the strengthening of concrete structures. An insight may be obtained from the discussions made to enhance the use of these techniques for productive use. In addition, selected case studies have been furnished where FRP materials have been used for repairing/retrofitting, emphasizing the application of different types of FRP materials in strengthening concrete structures. Concludes that the use of FRP material is rapidly gaining pace and replacing the traditional steel or metal based materials due to its enhanced properties and cost effectiveness.

The compressive strength of concrete depends on many interdependent parameters; its exact prediction is not that simple because of complex processes involved in strength development. This study aims to predict the compressive strength of normal concrete and high-performance concrete using four datasets.

In this paper, five established individual Machine Learning (ML) regression models have been compared: Decision Regression Tree, Random Forest Regression, Lasso Regression, Ridge Regression and Multiple-Linear regression. Four datasets were studied, two of which are previous research datasets, and two datasets are from the sophisticated lab using five established individual ML regression models.

The five statistical indicators like coefficient of determination (R²), mean absolute error, root mean squared error, Nash–Sutcliffe efficiency and mean absolute percentage error have been used to compare the performance of the models. The models are further compared using statistical indicators with previous studies. Lastly, to understand the variable effect of the predictor, the sensitivity and parametric analysis were carried out to find the performance of the variable.

The findings of this paper will allow readers to understand the factors involved in identifying the machine learning models and concrete datasets. In so doing, we hope that this research advances the toolset needed to predict compressive strength.

Use of fibre‐reinforced polymer (FRP) composite rods, in lieu of steel rebars, as the main flexural reinforcements in reinforced concrete (RC) beams have recently been suggested by many researchers. However, the development of FRP RC beam design is still stagnant in the construction industry and this may be attributed to a number of reasons such as the high cost of FRP rods compared to steel rebars and the reduced member ductility due to the brittleness of FRP rods. To resolve these problems, one of the possible methods is to adopt both FRP rods and steel rebars to internally reinforce the concrete members. The effectiveness of this new reinforcing system remains problematic and continued research in this area is needed. An experimental study on the load‐deflection behaviour of concrete beams internally reinforced with glass fibre‐reinforced polymer (GFRP) rods and steel rebars was therefore conducted and some important findings are summarized in this paper.

Fibre reinforced polymer (FRP) materials are currently used for concrete structures in areas where corrosion problems are serious. Recent applications of FRP rebars in normal reinforced concrete structures in fact cannot fully utilise the strength of FRP. A more rational use of FRP would be in the area of prestressed concrete (PC) structures. In spite of the superb strength provision of FRP tendons over steel tendons, use of FRP PC members is often questioned by practising design engineers. This is largely due to the brittleness of FRP tendons and lack of ductility in FRP RC structures. Recent research has demonstrated some important findings in promoting the confidence of adopting FRP RC beams. This paper reviews some recent work on the use of FRP in PC structures. Future possible research areas are also highlighted.

Discusses the properties of pulverized fuel ash (PFA) concrete both in its fresh and hardened states, with emphasis on aspects which are relevant to warmer localities such as Hong Kong. Sufficient research evidence, including surveys of existing structures, have been reviewed to conclude that PFA, when used correctly and properly, has the potential to enhance the performance of good concrete. Analyses the contribution of PFA in the enhanced performance of concrete. Cautions that much of the enhanced performance depends on the microstructure of the concrete, which in turn depends significantly on a proper mix design, with or without PFA. Proposes that water reduction is a desirable property of PFA. However, considers it possible to accommodate PFA characteristics in the mix design and by the use of plasticizer to produce good quality PFA concrete. Briefly discusses the characteristics of Hong Kong locally produced PFA.

Discusses the results of a study of the moduli of elasticity of concretes made with artificially manufactured lightweight aggregates subjected to uniaxial compression and uniaxial tension. Two artificially manufactured lightweight aggregates and one normal weight aggregate (for comparison) were used in the investigation. Concrete mixes designed to have compressive strengths varying from 20 MPa to 60 MPa were used in this study. Presents the results of static and dynamic moduli of elasticity, Poisson′s ratio, ultrasonic pulse velocity, compressive strength and tensile strength tests. Observes that the static modulus of elasticity in tension is nearly equal to the static modulus of elasticity in compression at a stress level of one‐third the ultimate stress. Compressive modulus values are shown to be dependent on the stress level and type of modulus, i.e. either secant or tangent. On the other hand, the tensile modulus is not affected by the stress level. The modulus of elasticity of lightweight aggregate concrete is about 60‐70 per cent of that of normal weight concrete. Compares the test results obtained in this study with research work carried out on other lightweight aggregate concretes by other investigators. Also presents the relationships between static modulus of elasticity, dynamic modulus of elasticity, compressive strength, and Poisson′s ratio, and equations for estimating elastic modulus and Poisson′s ratio.

Debonding, leading to the subsequent detachment of applied finishes to concrete buildings, is becoming a serious problem in many parts of the world. Checking building elevations by employing the technique of Infra‐red Thermography using a process developed by the writer can give advance warning of potential defects. This can enable early remedial action to be undertaken to repair a building surface before it becomes detached from the concrete substrate, possibly resulting in a hazard to passers‐by. The thermographic test method has been compared with other more traditionally used NDT methods including sounding, rebound hammer, and ultrasonic pulse velocity measurements. Although the thermographic equipment is initially more expensive, the surveying method can be shown to be faster and more accurate than any other technique currently available for this type of building evaluation.

This paper offers a brief review of the present use of scanning electron microscopy (SEM) in concrete studies, from the perspective of how research in materials science is translated into applications in construction engineering. It describes the scope of present use of the method, and attempts a prospective for the near future in areas where more work could make productive use of the technology. Selected case studies have also been discussed. The electron microscope has been used as a research tool in understanding the root cause of the differing performance of various types of concrete under various conditions, a development tool in making better concrete, and a diagnosis tool on problems like cracking of concrete. The paper also explains how sample preparation affects the type and quality of information which the SEM can produce.