Seismic Performance of Masonry-Infilled RC Frames and Its Implications in Design Approach: A Review

Predicting the seismic response of masonry-infilled (MI) RC frames holds immense importance due to the significant influence of masonry on the structural performance. Despite numerous studies delving into the seismic behavior of these frames, their complex interaction of masonry infills and RC frame presents ongoing challenges for researchers, designers, and standards committees. Although numerous studies have been conducted to investigate the seismic behavior of masonry-infilled reinforced concrete frames, its complex behavior poses a challenge to researchers, designers, and the specification-making committees. In recent years, several national codes have been revised to include the estimation of the stiffness of reinforced and nonreinforced masonry walls and have provided guidelines for the modeling and analysis of structures considering MI. This article aims to provide a comprehensive review of how infilled masonry walls impact the seismic performance of RC frames, drawing comparisons with codal provisions. The focus lies on scrutinizing experimental, numerical, and analytical studies that explore in-plane and out-of-plane behaviors. Factors like masonry strength, stiffness, area of openings, stiffness degradation, energy dissipation capacity, and damage patterns are thoroughly examined. Key findings with critical implications are highlighted, shedding light on potential future research directions in this crucial field

Influence of ground-granulated blast-furnace slag on the structural performance of self-compacting concrete

In the last decades, the utilization of industrial waste like ground-granulated blast-furnace slag (GGBFS) has proven itself a great asset in the modern construction industry. Aiming at promoting the green housing initiatives, the present study focused on the study of the influence of GGBFS on the structural performance of self-compacting concrete (SCC). In the initial phase of the extensive experimental program, concrete cubes were prepared with the partial replacements of GGBFS (10%, 15%, 20%, 25%, and 30% with cement) and tested against the control mix in order to investigate the associated mechanical properties (compressive strength, tensile splitting strength, and flexural strength). At 20% GGBFS replacement, the optimum compressive strength was noted, and further addition of GGBFS caused a gradual decrease in the mechanical strength properties. This study further investigated the structural properties like axial load-displacement behavior and failure pattern of RC columns and flexural performance of RC slabs with and without the addition of GGBFS. SCC with 20% GGBFS demonstrated relatively better structural performance, causing the formation of smaller crack width/depth/length compared with the control mix. An empirical relationship was also proposed based on the experimental test results (in relation to the mechanical properties) in line with US and Indian standards code of practice

Utilization of Bottom Ash and Pond Ash as a Partial Replacement for Sand in Cement Mortar and Concrete: A Critical Review

The rapid depletion of natural building materials is mainly caused by the exponential increase in construction operations. The need for and inevitability of finding alternative building materials to partially replace traditional materials in construction are unavoidable. In this study, the idea of using pond ash and bottom ash as a partial replacement of fine aggregates in concrete is examined, and the effects of pond and bottom ash on the fresh and mechanical properties of concrete are investigated, as reported in the literature. Being affected by the coal burning system, the chemical and physical properties of pond ash and bottom ash vary across various sources and years of investigation. Many experiments have shown that bottom ash and pond ash can be used in the right proportions to provide workability and increased strength of concrete. The idea of turning a variety of waste into wealth to conserve essential green space is backed by nearly every academic. Again, the increased use of fly ash (FA) and pond ash (PA) as an alternative to river sand will reduce river sand extraction and ensure the long-term stability of a green river ecosystem

Strength and Stiffness Evaluation of a Fiber-Reinforced Cement-Stabilized Fly Ash Stone Dust Aggregate Mixture

The utilization of waste fly ash in road construction is primarily confined to its use in embankment filling or as a stabilizer when combined with lime and cement. Its application in structural pavement layers, such as the base and subbase, faces a challenge due to the high volume of fine particles, which renders it brittle when stabilized. In this study, fly ash was blended with stone dust and aggregated to enhance its gradation. Subsequently, it was stabilized with cement to bolster its strength, rendering it suitable for pavement use. Additionally, polypropylene (PP) fibers were introduced to mitigate the brittleness of the mixture. An extensive experimental investigation was conducted to assess the strength and stiffness properties, including compressive strength, indirect tensile strength, flexural strength, cyclic indirect tensile modulus, and flexural modulus of fiber-reinforced cement-stabilized mixtures of fly ash, stone dust, and aggregate. The experimental results reveal that the addition of PP fibers up to 0.25 wt.% enhances compressive strength, but any further increase in fiber content leads to a reduction in strength. However, indirect tensile strength and flexural strength show improvement, with an increase in fiber percentage up to 0.5 wt.%. It was observed that cement content plays a dominant role in stabilizing these materials. Appropriate relationships have been established between strength and modulus parameters for stabilized mixtures. Based on the strength and stiffness study, a combination of 70% fly ash and 30% stone dust aggregate with 6% cement can be considered for the base layer. Regarding the behavior of indirect tensile strength and flexural strength, an optimum fiber percentage of 0.35% is recommended

Durability, Capillary Rise and Water Absorption Properties of a Fiber-Reinforced Cement-Stabilized Fly Ash–Stone Dust Mixture

The management of unutilized fly ash poses challenges due to concerns about storage and its potential groundwater contamination. Within the road industry, where the bulk utilization of fly ash is feasible, its unsuitability for use in the base and sub-base layers of pavements due to its low strength and a high proportion of fine particles has been a limitation. The incorporation of stone dust alongside fly ash, treated with lime or cement, yields superior strength and stiffness. Apart from strength, the stabilized mix’s durability, capillary rise, and water absorption properties are crucial for determining its suitability for pavement applications. Observations from this study reveal that fiber-reinforced cement-stabilized fly ash–stone aggregate specimens treated with 4% and 6% cement, with and without fibers, met the limiting mass loss of 20%, as specified in IRC SP: 89. The mass loss decreases with an increase in cement and fiber content. However, the capillary rise in the mixes increases with a higher percentage of fly ash and fiber content but decreases with increased cement content. Cement addition results in a reduction in water absorption; however, the addition of fibers results in an increase in water absorption. A linear correlation has been established between mass loss and UCS and IDT, which can be used to evaluate the suitability of materials for the structural layer without conducting a wet–dry durability test, which typically takes one month. This study proposes that cement-stabilized fly ash and stone aggregate mixtures with 4% and 6% cement can be used as the subbase and base of pavement based on wet–dry mass loss criteria and water absorption criteria. Observations from this study reveal that fiber-reinforced cement-stabilized fly ash–stone aggregate specimens treated with 4% and 6% cement, with and without fibers, met the limiting mass loss of 20%, as specified in IRC SP: 89. The mass loss decreases with an increase in cement and fiber content. However, the capillary rise in the mixes increases with a higher percentage of fly ash and fiber content but decreases with increased cement content. Cement addition results in reduction in water absorption. However, the addition of fibers results in increase in water absorption. A linear correlation is established between mass loss and UCS and IDT, which can be used to evaluate the suitability of materials for the structural layer without conducting wet–dry durability tests, which take one month. This study proposes that cement-stabilized fly ash and stone aggregate mixtures with 4% and 6% cement can be used as the subbase and base of pavement based on wet–dry mass loss criteria and water absorption criteria