Innovative Infrastructure Solutions

Lateef, Assim Mohammed; Ahmed, Shamil K.; Mohammed, Hasan Jasim

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01213-7

Encouraged by the pressing demand for improving the resilience and performance of critical structural elements such as columns, an innovative lateral reinforcement was introduced and investigated in this paper with the potential of increasing the strength capacity as well as the ductility and failure configuration. The traditional lateral ties of the circular RC column were replaced with a steel wire mesh confinement and then tested experimentally. Six columns were examined under concentric compression axial load up to failure in three groups in addition to the reference column. The impact of core diameter and the number of mesh layers was evaluated. The results showed that the proposed lateral reinforcement has a positive impact on increasing the strength capacity compared with the traditional lateral ties by up to 9.5%. A specimen with two layers of wire mesh in two core diameters of 80 mm and 100 mm, respectively, showed enhanced performance in bearing capacity, ductility index, and dissipated energy by 7.5%, 6.7%, and 16%, respectively, compared to the column reinforced with conventional lateral ties.

Ganesh, A. Chithambar; Raju, Hemadri Prasad; Prasad, J. Ram; Mukilan, K.

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01241-3

This study presents an in-depth investigation into the utilization of granite waste as a partial replacement for the M-sand in geopolymer concrete in various proportions such as 5, 10, 15, and 20%. Geopolymer in this study is made using GGBS as the precursor material and RHA-based derivative as the activator solution. The experimental research focuses on geopolymer concrete that is activated using a derivative of rice husk ash (RHA). The primary objective is to assess the potential enhancement of mechanical properties and durability characteristics by incorporating granite waste powder. A series of tests were conducted to evaluate the effects of varying levels of granite waste powder and RHA derivative on properties such as compressive, tensile, and flexural strengths, water absorption, chloride penetration resistance, and resistance to acid attack. Followed by the scrupulous discussion part, SEM analysis is performed to determine the morphology of the optimum specimen. The research revealed enhanced mechanical and durability properties at 10% utilization of granite waste due to the improved microstructure with reduced porosity owing to the fine and angular nature of granite waste. Additionally, geopolymer concrete activated with the RHA derivative demonstrates promising potential as a sustainable alternative to conventional alkaline activators. These findings contribute valuable insights to the field, offering a sustainable approach to enhancing geopolymer concrete properties while minimizing environmental impact.

Kotwal, Akhilesh; Deb, Plaban

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01244-0

Environmental problems including urban heat islands, waterlogging, pollution and catastrophic climates occur frequently and on a worldwide scale. Pervious concrete pavement (PCP) has some benefits in fighting against such environmental problems as it enables greater rainwater drainage, thereby reducing the urban heat island effect, fostering ecological balance in cities and resolving urban flooding. However, the porousness reduces its overall strength and the use of some additives becomes inevitable. This study uses silica fume as an additive to the PCP to improve its strength and aims to investigate how silica fumes affect the characteristics of environmentally friendly pervious concrete. The silica fume is added to the PCP matrix in three different ratios (2, 4 and 6%), and compressive strength, flexural strength and split tensile strengths of silica fume-modified PCPs are evaluated. Further, porosity and permeability are also investigated as these are the key parameters to maintain water percolation. The test results confirmed that adding silica fume improved the strength of PCP specimens. Compressive strength increases about 2.2 times and 3 times when 4 and 6% silica fume are added to the mix. Similarly, split tensile strength and flexural strength have increased by 9–10%, 25–36% and 39–49% when 2, 4 and 6% silica fume are added to the mix. However, there was no notable change in the porosity and permeability of the PCP mixes and the values range within ± 5%.

Baradaran, Mohammadreza; Sadeghpour, Mahmoud

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01222-6

Recent years have seen increasing interest in the use of bacteria to induce self-healing properties in concrete. In this study, the effect of Bacillus subtilis, Bacillus megaterium, and Sporosarcina pasteurii on the self-healing, durability, and strength properties of concrete containing zeolite was investigated. Four different concentrations of these bacteria were tested to determine the optimal concentration of each strain. Bacillus subtilis was isolated from alfalfa stems and leaves and Bacillus megaterium and Sporosarcina pasteurii were acquired as lyophilized ampoules and cultured in the laboratory. For zeolite-containing specimens, the mix design was modified to replace 20wt% of cement with zeolite. Four series of destructive and non-destructive tests including ultrasonic pulse velocity (UPV), impermeability, water absorption, and compressive strength tests were conducted on the specimens at different ages. To determine the effect of bacteria on the self-healing property, 3-day-old specimens were put under a load equal to 30% of the fracture load so that they would develop cracks and then imaged by a scanning electron microscope (SEM) and an optical microscope to examine the progress of self-healing. An energy-dispersive X-ray spectroscopy (EDS) analysis was also performed to identify the constituting elements of the specimens. The optimal concentration of each type of bacteria for maximum self-healing was determined from experimental results. The results showed that the best bacterial concentration for producing calcite and filling cracks and voids in concrete is 2.8 × 108 for Bacillus subtilis and 105 for Bacillus megaterium and Sporosarcina pasteurii. Using these concentrations resulted in enhanced compressive strength, lower permeability, lower water absorption, and improved UPV. The introduction of bacteria to the mix design decreased the concrete’s water absorption by 15% in the absence of zeolite and by 30% in the presence of zeolite.

Ashok, M.; Jayabalan, P.; Joseph, J. Daniel Ronald

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01226-2

In this research work, an attempt is made to use chemically treated and un-treated recycled plastic waste as a partial replacement for fine aggregates in the production of concrete and to evaluate its mechanical properties. The recycled plastic waste (RPW) fine aggregates were treated to improve the adhesion properties of recycled plastic waste with the adjacent cementitious matrix. Both M20 and M40 grades of concrete were considered for the present study. The concrete specimens were cast with 0%, 5%, 10%, 15% and 20% of treated recycled plastic waste (T-RPW) and un-treated recycled plastic waste (UT-RPW) fine aggregates to determine mechanical strength. The thermal behaviour of the concrete specimens with and without recycled plastic waste was also investigated. The specimens were exposed to elevated temperatures in a range 100 °C to 500 °C. Reduction in compressive strength and mass loss were evaluated to investigate the effect of including treated and un-treated RPW fine aggregates on the mechanical performance of concrete at elevated temperatures. The microstructural properties of concrete such as SEM and XRD were also investigated. Test results indicated that the compressive strength of concrete increased with an increase in temperature up to 100 °C beyond which strength decreased. The percentage decrease in compressive strength was 60.0% and 49.2% for 20UT-RPW and 20 T-RPW, respectively, at 500 °C. Greater strength loss was observed at 500 °C due to the decomposition of the RPW fine aggregates and hydration products. Increase in the percentage of RPW fine aggregates and increases in temperature increased the mass loss of the specimens.

Murugesan, Arun; Umapathi, Nandhini; Mohamed Ismail, Abdul Aleem; Srinivasan, Deepasree

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01228-0

The research work aims at outbreaking the fundamentals by distinguishing the varying superplasticizers by its workability, strength, and behavior on Ultra-High-Performance Concrete (UHPC). The UHPC works under a low water-binder ratio where the workability is maintained through the addition of superplasticizers. Superplasticizers are of four types, namely Sulphonated Naphthalene Formaldehyde (SNF), Sulphonated Melamine Formaldehyde (SMF), Sulphonated Acetone Formaldehyde (SAF), and Polycarboxylate Ether (PC). The present research work is a comprehensive study focusing on the influence of superplasticizers such as type, dosage, fresh, and hardened state properties on UHPC. With this background, the present study was carried out to analyze the performance of UHPC through three types of superplasticizers such as SNF based—Hi-plast S50, SMF based—BPC—M20, and PC based—Master Glenium 51 at a consistent dosage of 0, 0.5, 1, 1.5, and 2%, respectively, with a constant percentage of glass fiber (2.5%) and silica fume (15%) to the weight of cement. Out of three superplasticizers, PC-based admixture showed a good impact with moderate workability retention and water reduction of 20–35%. The saturation dosage was attained at 1.5% of PC-based admixture. The outcome of the present study is expected to break through the fundamentals of superplasticizers and their applications in UHPC. Based on the observation, it is recommended that PC-based admixtures are more prominent than sulphonated superplasticizers in terms of water reduction, workability, and strength aspects.

Alghamdi, Hussam; Shoukry, H.; Perumal, Priyadharshini; Khawaji, Mohammad; Abadel, Aref A.

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01231-5

Lightweight construction materials have received extensive attention due to their better thermal insulation, which helps improve energy efficiency in buildings. This study aimed at developing lightweight, thermally resistive and fire-protective green plastering mortar by adopting the low-carbon LC3 binder. A green and economical ternary blended binder has been prepared by substituting 60 wt% of the ordinary Portland cement with a blend of limestone powder and metakaolin at a ratio of limestone to metakaolin of 1:2 (wt%). The binder has been blended with expanded polystyrene (EPS) beads as fine aggregate with different aggregate contents of 25, 50 and 75 vol. %. Polypropylene microfibers were added at a constant ratio of 0.5% by weight of binder. The compressive and flexural strengths, capillary water absorption, bulk density, thermal conductivity, fire resistance and microstructure of the developed mortars were studied after 28 days of hydration. The newly developed LC3 fiber-reinforced mortar complies with the standard recommended criteria of lightweight and thermal insulation characteristics, with a density as low as 654 kg/m3, a thermal conductivity as low as 0.18 W/mK and an improved compressive strength of 11.89 MPa. The integration of EPS into the fiber-reinforced LC3 binder has distinctly provided an enhanced fire resistance rating; the greatest enhancement of about 125% was attained for the LC3 lightweight mortar with 50 vol. % EPS.

Bekkeri, Gopal Bharamappa; Shetty, Kiran K.; Nayak, Gopinatha

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01227-1

In the construction sector, the material supply chain of aggregates is frequently disturbed due to seasonal unavailability, quarrying issues, and environmental norms. The production of artificial aggregates has gained prominence to conserve natural resources and promote green construction practices. The current study encompasses the production of alkali-activated artificial aggregates through cold-bonding pelletization technique using three different raw materials, including fly ash, ground granulated blast furnace slag, and seashell powder in binary and ternary blending combinations. The cold bonding was achieved by alkali activation of binders with the aid of a sodium-based alkaline solution, which acts as an activator and hydrating liquid. The fresh artificial aggregates were subjected to surface treatment using the same alkaline solution to enhance their characteristics. The mechanical properties of artificial aggregates confirmed their potential as a substitute for conventional aggregates by exhibiting crushing and impact values of 18.19–27.53% and 12.06–18.85%, respectively. The microstructural and mineralogical characteristics depicted dense microstructure and compact matrix. The study concludes that artificial aggregates can effectively replace natural coarse aggregate in making structural concrete with many economic, environmental, and technical advantages.

Rathinavel, Nidhya; Murugesan, Arun; Ismail, Abdul Aleem Mohamed

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01238-y

Certainly, the presence of cracks plays a pivotal role in assessing the structural integrity of civil infrastructure. The existence of early age cracking in concrete presents a considerable risk to the long-term durability of structures. In the field of crack detection, numerous techniques are available, among which crack luminescence stands out as an innovative and easily accessible method for identifying incipient cracks. In this study, the luminescent properties of sulfonated acetone formaldehyde (SAF) were examined in conjunction with vinyl acetate ethylene (VAE) for the purpose of detecting cracks in a substrate. The progression of cracks was systematically monitored and recorded under 365 nm UV radiation. The severity of the cracks was analyzed in relation to different flexural stress and strain conditions. In this study, crack initiation was observed at a flexural strain of 1.2%, corresponding to a stress of 1.1 MPa. Subsequently, mild crack propagation was observed on both sides of the specimen at a strain value of 1.5%, with a corresponding stress of 2.2 MPa. The failure occurs within a strain region of 2.1% and corresponds to a stress value of 5 MPa. Once the flexural strain surpasses 1.2%, crack propagation initiates, gradually accelerates, and leads to failure with a reduced strain rate. The results highlight the utilization of SAF-VAE-based mechano-luminescence as a crack detection sensor. This approach offers potential benefits for identifying and analyzing the severity of cracks in construction structures, leading to improved safety, timely maintenance, and enhanced structural integrity. This technology offers a reliable and efficient method for detecting and monitoring cracks, ultimately contributing to the overall safety and longevity of the built environment.

Anburuvel, Arulanantham

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01235-1

Geopolymer concrete has earned substantial attention over the years as it contributes to mitigating the detrimental impact on the environment caused by conventional binders. It synthesizes precursors and alkali activator to form geopolymer gel that binds aggregates. The limited supply of precursors has been one of the factors that prevent it from being adopted by the construction industry. At the same time, numerous waste materials and by-products are disposed in landfills, which could be exploited for use as precursors. To promote the usage of geopolymer, it is inevitable to introduce alternative precursor resources. Collectively reviewing alternative materials about their supply perspectives and application potential would help to find suitable replacements for precursors. Reusing waste materials as precursors reduce carbon footprint. This article presents a methodical review of the use of different types of precursor sources under various contexts, namely the type and supply of alternative precursors, chemical and physical properties, engineering aspects, and prospects. It is evident from the review that fly ash, ground granulated blast furnace slag, rice husk ash, metakaolin, recycled concrete aggregates, and recycled aggregate pavements exhibited commendable mechanical characteristics in comparison with their competing alternatives. Moreover, the combinations of fly ash, ground granulated blast furnace slag, or metakaolin also showed promising engineering properties. This review imparts state-of-the-art knowledge on the use of alternative precursor resources that would assist in choosing potential alternatives. This article also would contribute to improving the existing standard protocols that govern the use of precursors in geopolymer applications.

Kasinikota, Pardhasaradhi; Tripura, Deb Dulal

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01240-4

This paper aimed to study the effect of coir fibres and cement inclusion on the physico–mechanical, durability and strength properties of hollow interlocking compressed earth blocks (ICEBs). The effect of moisture content on block strength at the time of testing was also considered. In total twenty different types of blocks were prepared with cement contents (0% and 10%), fibre contents (0%, 0.3%, 0.6% and 0.9% by dry weight of soil) and lengths (30 mm, 50 mm and 70 mm). The blocks were tested in air-dry as well as in wet states. Scanning electron microscopy (SEM) analysis was made to know the microstructure of coir fibres and blocks. Also, correlations between mechanical properties were established. Furthermore, empirical models were derived for estimating the strength properties. Test results show that addition of 10% cement slightly increases the bulk density (ρ), substantially improves strength properties and remarkably decreases linear drying shrinkage (LDS). The inclusion of coir fibres to both ICEBs (unstabilized) and ICSEBs (stabilized) significantly reduces the bulk density (ρ), ultrasonic pulse velocity (UPV), and LDS, and increases the water absorption (WA). Addition of coir fibres significantly improves the mechanical strength of both types of blocks. Blocks reinforced with 0.6% fibre and 50 mm length possesses higher compressive, flexural and splitting tensile strength. The optimum fibre content and length were found to be 0.6% and 50 mm, respectively. On the other hand, higher fibre content (0.9%) and length (70 mm) adversely affected the strength and increases water absorption for all types of blocks. UPV test appeared to be ineffective in estimating the strength of ICSEBs when the reinforcing fibre content increases due to the presence of larger amount of air voids. A good linear relationship was obtained between the mechanical properties for the block types. The proposed models can be adopted to estimate the block strengths with reasonable accuracy.

Abd Elaty, Metwally Abd Allah; Azzam, Wasiem Ragab; Eldesoky, Ahmed Gamal

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01224-4

To make construction materials more sustainable and greener, companies must consider the environmental impact when sourcing materials include developing methods for sustainable recycling and encouraging design practices that prioritize the use of green materials using additives. Geotechnical applications including construction of cutoff walls require development of enhanced materials that possess certain attributes to ensure strain compatibility with surrounding soil. The study aims to explore the utilization of different materials such as bentonite, cement dust, fly ash, lime and polypropylene fibers to produce cement–bentonite mortar with low permeability and sufficient strength. For optimizing the process parameters in the experimental domain, an orthogonal array by Taguchi method was used, and thirty-two experimental runs were performed. The properties investigated included flow%, displaced volume rate, compressive, splitting tensile, flexural, shear strengths, elastic modulus and permeability coefficient. The test results demonstrated that cement dust, fly ash and lime could achieve optimal performance in terms of low permeability and sufficient strength. Additionally, polypropylene fibers up to 0.3% could be effectively used to achieve sufficiently low elastic modulus without affecting other conductive strengths significantly. The findings of the regression model demonstrated that the developed models could account for how the independent variable affected the necessary responses. This study could provide engineers with insights into selecting the appropriate materials to achieve the desired performance characteristics for some geotechnical applications considering sustainability.

Miah, Md Jihad; Huaping, Ren; Paul, Suvash Chandra; Babafemi, Adewumi John; Li, Ye

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01225-3

Research has shown that adding supplementary cementitious materials (SCMs), such as fly ash (FA) and slag (SL), to concrete improves its mechanical and durability properties up to certain limits. However, the long-term performance of concrete made with FA and SL is not fully known. This study investigates the impact of FA and SL on the long-term (up to 900 days) performance of concrete. The concrete specimens were made with six replacement percentages (0, 10, 20, 30, 45 and 60 by weight) of ordinary Portland cement (OPC). The short-term fresh and hardened properties of all concrete mixes were assessed after 14, 28, 60, and 90 days of water curing. After 120, 365, 730, and 900 days of water curing, the long-term performance was investigated for 100% OPC (control), 30% FA, and 30% SL concretes. At 28 days, no significant difference in strength development was observed for the concrete mixes containing up to 30% FA and 30% SL than the control concrete (100% OPC). In contrast, a remarkable enhancement in strength development was registered for all mixes containing up to 30% FA and 30% SL at 60 and 90 days of tests. Likewise, 30% FA and 30% SL showed the lowest porosity and water absorption than the control. The mechanical strength of concrete prepared with 30% FA and 30% SL gradually rises over time (from 14 to 900 days) compared to the control concrete. With increasing concrete age, a reduction in porosity and capillary water absorption was seen (up to 900 days).

Deepak, M.; Ramalinga Reddy, Y.; Nagendra, R.

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01234-2

The use of ladle slag as a replacement for natural aggregates as coarse aggregate in concrete has gained attention in recent years due to its potential benefits in terms of sustainability and waste reduction. The paper aims to investigate the influence of ladle slag as a coarse aggregate replacement on various properties of concrete, including strength, durability, and microstructural changes. The paper may specifically investigate the strength improvement of concrete with ladle slag as coarse aggregate by varying the curing period, comparing the results at 7, 14, and 28 days of curing. In this study, experimental investigations are conducted using 100% Portland slag cement (PSC), 100% processed granulated blast furnace slag sand (PGBFS, iron slag) and partial or full replacement of natural coarse aggregates (NCA) with ladle slag coarse aggregate (LSA) with 0%, 20%, 40%, 60%, 80%, and 100% variations. Results showed the highest increase in compressive strength, flexure strength and high resistance to acid attack in concrete with 20% LSA replacement. Further, to optimize the ladle slag aggregate content, concrete mix with LSA content varying from 5 to 25% was tested, and maximum improvement with 20% LSA was observed. The moderate resistance against chloride permeation is exhibited by concrete mix with LSA, and microstructure shows increased porous structure compared to PSC, indicating the development of C–S–H and the link between C–S–H gels. The diffractograms show the presence of quartz aligned with alite and belite, which is known to result in a high amount of C–S–H gels and an increase in durability.

Natarajan, Karthiga Shenbagam; Ashokan, Mohanraj; Vellaipandian, Kannan

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01239-x

This research article focuses on the effects of marble waste (MW) and micro silica (MS) in self-compacting concrete (SCC). An attempt is made to utilize this waste material effectively in concrete. The physical, mineralogical and chemical properties of MW, MS and Ordinary Portland Cement were examined. The controlled concrete with 0% waste was replaced with 5–20% MW and 10–40% of MS to attain the target strength of M40. Latest generation super plasticizer, Auromix 400, is used to enhance the fresh properties of concrete. In accordance with the European Federation for Specialist Construction Chemicals and Concrete Systems (EFNARC guidelines), the workability properties of SCC were studied using Slump flow, L-box and V-funnel test. The mechanical properties such as compressive, split tensile strength and durability tests like water absorption, permeability and rapid chloride penetration test on hardened concrete were examined at various curing ages from 7, 28 and 56 days, respectively. From the experimental tests, it can be concluded that 15% and 30% of individual replacement of MW and MS improved the mechanical properties of SCC to 45%. Further 30% improvement in strength was observed with the combined replacement of 15% of MW and 30% of MS. The same replacement enhanced the durability properties of SCC. Micro-structural studies were carried out to examine the porous and morphological nature of SCC. Overall incorporation of MW and MS in concrete production could be effectively used in concrete, thus making the environment pollution free.

Revathy, J.; Yaswanth, K. K.; Gajalakshmi, P.

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01236-0

An innovation that transforms the brittle nature of the concrete to behave almost like a metal with 100% eco-friendly binding materials is called as Engineered geopolymer composites. Researchers opted for fly ash and silica sand to prepare engineered geopolymer composites for applications and research; however, the effect of other major ingredients has to be studied to favour the advantage of local availability. Engineered geopolymer composites, with a material combination of GGBS, RHA and Copper slag, have been prepared and optimised with respect to mechanical, durability and microstructural considerations in a previous research study from which the optimised mix was considered as a retrofitting material over cement concrete and geopolymer concrete beams, in this research. Engineered geopolymer composites with the thickness of 10, 20 and 30% to the overall depth of beam was layered underneath the concrete beams which resembles the retrofit method of chipping and layering. Eight ‘Layered beam’ specimens were prepared and tested upon flexural load in terms of load-carrying capacity, flexural, ductility and cracking characteristics. Results revealed that layering with ductile material significantly enhances the load-carrying capacity and flexural strain capacity. 30% layering of developed composite around the tension zone of the beam imparts the strain hardening nature, improves the multiple micro-cracking mechanism and enhances the maximum load up to 40 and 60% of cement and geopolymer concrete beams, respectively. 10% layering which implies clear cover to beam, also showed significant enhancement in maximum load that connotes the pure ductile nature of the material.

Al-Hadithi, Abdulkader Ismail; Almawla, Sara Ali; Mohammed, Mahmoud Khashaa

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01223-5

The aim of this study is to evaluate fresh, mechanical, and impact resistance of structural lightweight self-compacting concrete with good thermal insulation and incorporating waste PET fibers with different volume fractions and aspect ratios. Integration of the characteristics of self-compacting concrete, which are followability, good strength and sustainability with the characteristics of lightweight concrete, represented in reducing the loads of the structure and thermal insulation, in addition and with reducing the environmental damage represented by plastic by utilizing a fiber is the goal of this research. As a first stage of this study, lightweight Ponza aggregate was used as a coarse aggregate, as four reference mixtures were produced with volume replacement ratios of coarse aggregate volume ranging from 20 to 100%, and a reference mixture was produced for the purpose of comparison. In the second stage of this study, the performance of self-compacting lightweight concrete SCLC reinforced with waste PET fibers were analyzed in terms of fresh, physical, mechanical, and thermal properties as well as its flexural toughness and impact behavior. Nine different fiber reinforced self-compacting lightweight concrete were designed using waste plastic fibers WPF at three different volume fraction (0.5%, 0.75%, and 1%) and three different aspect ratio (15, 30, and 45). After design process, similar properties in the first stage in addition to toughness and impact test were performed. The results of second stage verified that the adding WPF to SCLC leads to reduction in dry density, ultrasonic pulse velocity, and thermal conductivity around 9%, 14%, 19%, respectively, with increase in PET fibers ratio from 0 to 1% at aspect ratio of 45. Further, the result of flexural toughness test showed that the use of WPF in SCLC leads to an interesting improvement in the post-cracking performance and enhanced ductility of concrete. Furthermore, there is substantial improvement in impact resistance of all WPF-reinforced SCLC mixes over control mix. Results clarified that WPF concrete mix of volume fraction 1% and aspect ratio 45 gave the best impact resistance, the improvement of its impact resistance at ultimate failure over control mix was 373.3%.

Thakur, Ranbeer; Tiwary, Aditya Kumar

2023 Innovative Infrastructure Solutions

doi: 10.1007/s41062-023-01229-z

This research paper presents an in-depth investigation into the seismic response of hybrid structures integrated with fluid viscous dampers (FVDs) and base isolation. Severe seismic events pose hazardous threats to hybrid structures, making it imperative to develop effective strategies for enhancing their seismic resilience. The study aims to assess the seismic performance of hybrid structures featuring Circular Hollow Section (CFST) and concrete-encased steel (CES) columns in comparison with conventional columns in RCC structures, leveraging the attributes of both FVDs and base isolation. Finite element analysis is employed to model the hybrid structure, and performance evaluation is conducted based on key parameters, including inter-story drifts, fundamental time period, stiffness, story displacements, base shear and overturning moments, utilizing the response spectrum approach. The study focuses on 16-story hybrid structures, having three different shapes of CFST and CES columns, incorporated individually with FVD, Lead Rubber Bearings (LRB) isolators, and a combination of both. To foster a more comprehensive understanding, the dampers are placed at two different heights, i.e., H and H/2 height of the building. The results demonstrate a noteworthy reduction in the structural response of the hybrid structure when subjected to seismic events through the integration of FVDs and base isolation. Comparative analysis of each energy-dissipating system reveals that a synergistic combination of FVDs and base isolation yields superior performance compared to their individual use. By bridging the existing research gap and investigating the intricate behavior of hybrid structures equipped with FVDs and base isolation, this research contributes significantly to the fields of earthquake engineering and structural resilience. The study contributes valuable insights into the advantages and limitations of each system, aiming to facilitate the development of safer and more resilient buildings, particularly in regions prone to high seismic activity.