Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

This work investigates grinding as a potential solution to improve the utilisation of low-quality fly ashes in concrete. Factors contributing to the performance of ground fly ash in cementitious composites were investigated. It was found that grinding significantly crushed large cenosphere particles and increased the specific gravity and surface area of fly ash, which led to a higher filler effect and improved the rate of cement hydration, contributing to strength development. The comparison of strength of quartz-blended pastes and fly ash-blended pastes showed that the pozzolanic reaction of fly ash marginally contributes to strength development. The major influence of ground particles was seen in the region near aggregates. Ground fly ash significantly increased the microhardness of the interfacial transition zone near aggregates. Since this zone has a direct influence on the failure of mortars and concrete, its improvement resulted in a comparable strength of fly ash-blended mortars to the reference ordinary Portland cement mortar. © 2022 ICE Publishing: All rights reserved.

World University root node

Department of Civil Engineering

Advances in Cement Research

Investigating the physical and chemical contribution of ground low-quality fly ash particles to cementitious composites

Heterogeneities in concrete manifest at various scales, from aggregates and its interfacial transition zone (ITZ) at macroscale to various hydration products at the microscale. On the application of load, cracks initiate from ITZ and propagate to the bulk cement paste (BCP), leading to the nonlinear stress-strain behaviour of concrete. This paper proposes a novel multiscale analytical approach to simulate the uniaxial stress-strain behaviour of concrete. Initially, the heterogeneous microstructure of ITZ and BCP is simulated using a cement hydration microstructure model (μic). Considering the gradient of phases in ITZ, aggregate gradation and aggregate volume fraction, stresses in the different phases in the ITZ and BCP are calculated by step-wise stress downscaling using continuum micromechanics. The initiation and propagation of cracks in the ITZ and BCP are modelled using damage mechanics. The efficacy of the current analytical approach is validated by comparing with the experimentally observed stress-strain curve. The current model investigates the relation between the macroscopic strain increment with the distribution of strain and the progression of damage in different ITZ layers. Through a parametric study, the influence of w/c ratio (0.30–0.50), aggregate volume fraction (30% and 50%), and aggregate size distribution on the stress-strain behaviour of concrete are discussed. © 2022 Elsevier Ltd

Mechanics of Materials

Multiscale modelling of uniaxial compressive stress-strain behaviour of concrete using analytical homogenisation and damage mechanics

This article reviews the rapidly developing state-of-the-art literature available on the subject of the recently developed limestone calcined clay cement (LC3). An introduction to the background leading to the development of LC3 is first discussed. The chemistry of LC3 hydration and its production are detailed. The influence of the properties of the raw materials and production conditions are discussed. The mixture design of concrete using LC3 and the mechanical and durability properties of LC3 cement and concrete are then compared with other cements. At the end the economic and environmental aspects of the production and use of LC3 are discussed. The paper ends with suggestions on subjects on which further research is required. © 2021 Elsevier Ltd

Cement and Concrete Research

Limestone calcined clay cement and concrete: A state-of-the-art review

The interfacial transition zone (ITZ) around aggregates is widely accepted as the weakest link in concrete that changes its elastic behaviour from brittle elastic to quasi-ductile on the application of external loads. In this paper, the influence of ITZ on the elastic properties of concrete is modelled using a multiscale micromechanics approach that includes the effects from the scale of the cement particles to the scale of aggregates. The approach considers the complexities present at different scales of concrete, such as aggregates of different types and size, microstructural features of the interfacial transition zone (ITZ) and bulk cement paste (BCP). The microstructure of ITZ and BCP is simulated using a vector based microstructural modelling platform (µic). The capability of the model to predict the elastic modulus of concrete is shown by comparing the model predictions with experimental results from the literature. Parametric studies on microstructural features of ITZ show that the preferential deposition of portlandite (CH) has a significant influence on the early age elastic modulus. Comparison of the predictions from the developed approach with predictions from the Mori-Tanaka method shows that the ITZ has the potential to reduce the macroscopic elastic modulus, however, the reduction in the elastic modulus in the ITZ is compensated by the increase in the elastic modulus of the BCP. © 2020 Elsevier Ltd

Construction and Building Materials

Influence of properties of interfacial transition zone on elastic modulus of concrete: Evidence from micromechanical modelling

Since fly ash is an industrial by-product, its properties are not controlled and, as such, are highly variable, leading to a high degree of variability in the performance of concrete. The feasibility of the blending of fly ashes in order to homogenize their properties was investigated by studying the variability in the heat of hydration and compressive strength of mortar mixes. All the mixes, including control mixes as well as blends, were prepared by replacing 30% ordinary portland cement (OPC) with either one fly ash or a blend of fly ashes. Blends of various fly ashes were prepared to homogenize their Blaine fineness, reactive silica content, and alumina content, the main parameters that influence the properties of concrete. It was found that blending the fly ashes, obtained from different sources, reduces the variability in the heat of hydration and the compressive strength. Single and double parameter blends were prepared to homogenize either a single or two parameters of fly ash by blending two or more fly ashes. It was observed that all the blends effectively reduced the variations in the hydration of cement and strength of cement mortars. Additionally, it was also found that homogenizing the Blaine fineness was the most effective means to reduce the variation in the performance of the mortars. © 2020 American Society of Civil Engineers.

Journal of Materials in Civil Engineering

Blending of Fly Ashes to Reduce Variability in the Heat of Hydration and Compressive Strength

This paper investigates the microstructural development of limestone calcined clay cements (LC3) using microstructural modelling. The microstructure of ternary blended cements containing 15, 30 and 45% limestone and calcined clay is simulated using microstructural modelling platform μic. It is found that replacing cement with limestone and calcined clay significantly increases the porosity of pastes. The increase in the porosity is observed to depend on the percentage replacement of cement with limestone and calcined clay. It is also observed that just the addition of fine limestone and calcined clays is not sufficient to explain the reduction in experimentally observed threshold pore diameter in pastes containing limestone and calcined clay. The results suggest that it is important to consider the modification in the hydration product (CASH) in order to explain the reduced threshold pore diameter of LC3 systems. © RILEM 2020.

RILEM Bookseries

Microstructural Modelling of the Microstructural Development of Limestone Calcined Clay Cement

Supplementary cementitious materials reduce the clinker factor in concrete. These mineral additives can vary in particle sizes (fine to ultrafine) and can influence mechanical properties and durability of concrete to a great extent. Durability of concrete depends on its intrinsic transport properties which further depend on the Interfacial Transition Zone (ITZ) present around aggregates. Available experimental investigations on the effect of fly ash on transport properties of concrete and mortar appear to be ambiguous, ranging from deleterious to enhancing effects to varying degrees. The present study examines the influence of fly ash on transport and mechanical properties of mortar and concrete to understand its influence on ITZ. Mortar and concrete having same aggregate volume fraction and water/cement ratio were tested for compressive strength, elastic modulus, oxygen permeability and sorptivity: variables include fly ash of different fineness with different percentage replacement. Same volume fraction of aggregates in mortar and concrete leads to a higher ITZ volume in mortar due to finer particle size distribution of aggregates. The strength and elastic modulus results shows that fly ash improves the mechanical properties of mortar more compared to concrete. The decrease in the fluid transport was also found more for mortar compared to concrete. This suggests that fly ash significantly improves the interfacial transition zone around aggregates. The improvement was found to increase with increasing fly ash fineness. © 2019 Associated Cement Companies Ltd.. All rights reserved.

Indian Concrete Journal

Influence of fly ash on mechanical and transport properties of concrete and mortar due to its effect on the interfacial transition zone

Interfacial transition zone (ITZ) is the region of cement paste adjacent to the aggregate surface. Large size aggregates disturb the packing of cement in their near vicinity due to wall effect and form ITZ. The microstructure of ITZ is more porous and has higher calcium hydroxide (CH) content compared to the bulk cement paste. ITZ has been considered the weakest link in concrete due to its microstructure. The presence of ITZ is the reason of lower strength of concrete compared to its constituents, cement paste, and aggregate. Effect of ITZ on the transport properties of concrete is still a subject of debate. Improving the microstructure of ITZ is a good way of improving mechanical and transport properties of concrete. This paper reviews various alternative methods used for improving the microstructure of ITZ. © 2019, Springer Nature Singapore Pte Ltd.

Lecture Notes in Civil Engineering

The interfacial transition zone: Microstructure, properties, and its modification

A new micromechanical model is developed for the prediction of the elastic properties of composite materials with embedded spherical multicoated inhomogeneities of various sizes and types. The model is based on the n + 1 phase model and the Mori-Tanaka homogenization. The model is capable of treating each coated spherical inhomogeneity individually, including specific attributes such as particle size and multiple mechanical phases. The accuracy of the model is assessed by comparing it with classical bounds and an analytical model from the literature. The results of the model are also compared with experimental data for the case of a three-phase composite material. The influence of mechanical properties and volume fraction of various constituents on the bulk elastic properties is also studied for the case of multiphase complex materials. © 2018 American Society of Civil Engineers.