Microbial-induced carbonate precipitation (MICP) is gaining attention as an eco-friendly and sustainable method for concrete crack repair. However, key challenges related to its large-scale implementation, regulatory approval, and integration into existing construction standards remain underexplored. This review examines recent advances in MICP, emphasizing its role in circular economy practices and sustainable building solutions. Traditional synthetic sealants contribute to environmental pollution and have limited long-term durability, highlighting the need for greener alternatives. Global research trends reveal an increasing focus on self-healing materials, biomineralization, and durability enhancement, alongside emerging innovations such as encapsulation technologies, marine applications, and bio-based composites. Unlike previous reviews, this study integrates bibliometric analysis to systematically assess research trends, identify key collaboration networks, and evaluate regulatory challenges that impact MICP adoption. While MICP offers significant advantages, including self-healing capabilities and compatibility with industrial by-products, barriers related to cost, scalability, and policy integration persist. This review identifies critical thematic clusters which include microbial action, sustainability, and engineering applications. This helps to provide actionable insights for researchers, engineers, and policymakers. By fostering interdisciplinary collaboration, MICP has the potential to become a transformative solution for resilient and environmentally sustainable infrastructure.
12 September 2017 in International Journal of Concrete Structures and Materials
This paper presents an experimental study of a new grouted splice connection for wall panels, called Welded Bar Sleeve (WBS). The connections were made from steel pipes and tested with incremental tensile, shear and flexural loads until failure. The aim is to determine the behaviour of the connection under the three load cases. For this, the connections are evaluated in terms of the load–displacement responses, ultimate capacities, ductility responses and some feasibility assessment criteria. WBS was found to provide sufficient strength at the bar embedded length of 8, 8 and 11 times the bar diameter under tensile, shear and flexural loads, respectively. It is effective under tension, but could only service up to 1/3 of its ultimate shear capacity. Flexural load is the most critical load case for the connection. For this, further enhancements are required when subjected to shear and flexural loads.
12 May 2023 in Journal of the Civil Engineering Forum
Ductility plays a crucial role in ensuring the safety of a structure, as its inadequacy can lead to sudden and brittle failure. Despite its significance, there is no explicit method for determining, leading to inconsistency and confusion in selecting appropriate techniques. Misjudging a structure’s ductile behaviour can have catastrophic consequences. Therefore, this study examined several preliminary studies and identified twenty-one methods for computing ductility indices. These indices were categorized into three types, namely conventional, displacement-based, and energy-based. The conventional ductility indices are commonly applied to steel-reinforced members, deformation-based ductility indices to FRP-reinforced members, and energy-based ductility indices to earthquake-resistant and static-load structures. Conventional ductility indices are specific to ductile reinforcements, while displacement-based and energy-based ductility indices apply to both ductile and non-ductile reinforcements. However, different calculation methods can lead to significant variations in the computed ductility, particularly for those involving the first crack, and load factor, thereby leading to different ductility requirements for ensuring structural safety. Additionally, not all methods are explicit, and it is crucial to avoid indiscriminately applying requirements from one method to another.
Construction of infrastructures on peat land is a very challenging task due to its properties of low shear strength, high compressibility and high water content. This paper summarizes various solutions which could be adopted for the construction of infrastructure on peat, as reviewed by the experts and panels during IConCEES International Workshop 2015. Engineers could (a) avoid peat, such as to transfer the load to the hard layers through end bearing piles or to replace the peat with the other soils, or (b) construct on peat with special precautions, such as by reducing the weight of the construction materials and dewatering the peat to improve the engineering properties. This paper serves to generate new ideas and give insights of the problems commonly encountered by the industry. Some of the proposed solutions might never be tested on peat. This would rely on the researchers to take up the challenge to further investigate and address the technical issues outlined in this paper.