Manu Santhanam

Manu Santhanam
Indian Institute of Technology Madras | IIT Madras · Department of Civil Engineering

PhD

About

239
Publications
149,082
Reads
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5,337
Citations
Additional affiliations
May 2003 - June 2003
Purdue University
Position
  • Visiting Instructor
October 2001 - present
Indian Institute of Technology Madras
Position
  • Professor (Full)

Publications

Publications (239)
Article
The buildability of a 3D printed concrete structure is influenced by the layer compression during printing, which in turn is governed by the rheological and early age mechanical properties of the mix. The study aims at understanding the effect of alkali-free aluminium sulphate-based accelerator on the microstructural evolution, which affects the ma...
Article
In this paper, the role of chloride transport parameter on the service life estimation of a reinforced concrete structure is discussed. The paper lists several qualitative and quantitative test methods used to measure resistance to ingress of chloride in concrete systems with their advantageous and critique. The relationship between the rapid asses...
Article
This article focuses on the specifics in characterizing the properties of additively manufactured, cement-based materials in their hardening and hardened states. Such characterization is required for the material development, structural design, and quality control of both printable material and 3D-printed elements. The related challenges are associ...
Article
Full-text available
This study is focused on increasing the workability retention of concrete with high replacements of cement by limestone calcined clay, or LC2 (≥45% by weight of binder). The effect of three commercially available PCE-based superplasticizers (SPs) on workability retention is studied. To enhance the retention ability of the concrete with SPs, a combi...
Article
The durability performance of blended cementitious systems with calcined clays is reviewed in this paper by the RILEM TC 282-CCL on calcined clays as supplementary cementititous materials (SCMs) (working group on durability). The impact of metakaolin and other calcined clays on the porosity and pore structure of cementitious systems is discussed, f...
Chapter
Extrusion-based 3D printed structures are heterogeneous with a combination of solid layers and weak bonds. The weak bonds can be considered to be an amalgamation of hydrated products and air voids. The hardened state properties of 3D printed structures depend on several factors such as layer strength, bond strength, geometrical imperfection, anisot...
Article
The effects of partially adding iron-oxide-modified aggregate to OPC-based pervious concrete filter on the mechanical properties, heavy metal removal and leaching were investigated. Up to 10% of both coarse and fine aggregates were coated with iron oxide and filters (IOMA-C, coarse alone modified, IOMA-F fines alone modified and IOMA-CF) were prepa...
Article
Full-text available
RILEM TC 267-TRM is studying tests for the reactivity supplementary cementitious materials (SCMs). In the first phase, the lime reactivity (LR) test, which is standardised in Indian standard (IS)-1727, gave promising correlations with 90-days cement mortar strength. In Phase 2, working group 1 has looked at further optimisation and robustness study...
Article
This study investigates the effect of the alkali-free aluminium sulfate based accelerator on the printability and buildability of 3D printable concrete. The accelerator is introduced at various locations in the printing system – at the mixer, nozzle and sprayed on the surface post-printing. The influence of accelerator on setting and hardening is e...
Article
This paper reports on the effect of preconditioning methods on oxygen permeability, sorptivity and water permeability of alkali-activated concrete. Effects of molarity and types of activators on the strength attainment of ground granulated blast furnace slag and fly ash based alkali-activated mortar are also presented. Moreover, a detailed investig...
Article
Full-text available
Cellulose poulticing is a widespread method of desalination in practice for removal of salts from ancient structures. Optimization of the process is essential, considering that poulticing/desalination is the prime step during the protection of existing structures in the coastal zones. Even though poulticing is widely used in European countries, it...
Article
Accelerated weathering tests are commonly carried out to evaluate the resistance of porous materials to the damage induced by salt crystallization. A wide range of testing procedures have been prescribed by various standards and recommendations to suit the spectrum of materials adopted in general construction. On account of the differences in the p...
Article
Supplementary cementitious materials (SCMs) can be used in concrete to enhance sustainability and reduce the concrete industry's carbon footprint. However, some negative perceptions about their long-term carbonation resistance are obstacles for large-scale implementation of such concretes. This study evaluated the carbonation resistance of 34 concr...
Article
A proper scientific fire damage assessment programme is important to ensure safety and adopt optimum restoration strategies in case of fire accidents to monuments. This paper proposes and demonstrates a comprehensive multiscale scientific framework for fire damage assessment carried out on a historical trabeated hypostyle stone structure constructe...
Article
Full-text available
This paper explores the sustainability aspects of binders used in concrete 3D concrete printing. Firstly, a prospective approach to conduct sustainability assessment based on the life cycle of 3D printed structures is presented, which also highlights the importance of considering the functional requirements of the mixes used for 3D printing. The po...
Presentation
The use of calcined clay as a substitute material has multiple effects on the evolving microstructure and significantly alters the durability performance of concrete systems. In this study, concretes prepared with calcined clay were characterized for resistance to chloride and moisture ingress using non-steady state chloride migration and unidirect...
Article
This paper evaluates the suitability of limestone-calcined clay (LC2) combination as a cement substitute material in concrete systems subjected to steam curing. Concrete with blends of Portland cement and LC2 were subjected to short-term heat curing and compared against concrete with plain portland cement and fly ash-based binder (at 30% replacemen...
Article
The objective of this work is to determine the interfacial strength between cement paste and epoxy, coated at the different instant of time during the hydration. The factors influencing the magnitude of interfacial adhesive strength were also studied. To pursue this, the interfacial adhesive strength between cement paste and epoxy coated at differe...
Article
In order to provide corrosion protection of tendons in post-tensioned (PT) concrete systems, the congested interstitial spaces between the strands and duct are ideally to be filled with cementitious grouts. However, many currently used grouts do not have the desired fluidity and resistance to segregation – leading to formation of voids, frothy grou...
Article
The review summarizes literature to examine the transition from portland limestone cement system to composite ternary binder systems involving limestone. Interest in limestone addition as an ideal component in multicomponent binder systems has surged as evident from the large volume of literature published in the recent past. A ternary blended syst...
Article
Full-text available
Porosity of a mortar significantly influences its mechanical characteristics as well as durability. To ensure compatibility while designing a repair mortar for historic masonry, it is important to have both a qualitative and quantitative description of the pore structure. In this paper, we present the porosity investigations of two types of historic...
Article
Full-text available
Surface coatings are mainly applied to protect concrete structures against various environmental conditions. However, the interface between the concrete and coating is a weak link, and interfacial delamination is the primary mode of failure. Fracture resistance is the main design criteria for these materials, and therefore, it is necessary to inves...
Article
Full-text available
This paper correlates the durability of bricks in various environments to their physical and micro-structural characteristics. Micro-analytical and physical characterisation techniques were employed to find the raw materials and firing temperature of the historic bricks. Mercury Intrusion Porosimetry (MIP) and Scanning Electron Microscopy (SEM) hel...
Chapter
Protecting the existing brick masonry structures efficiently is a part of sustainable development in the built environment. The effective choice of compatible products in such restoration process as described in this paper reduces the chances of future frequent interventions due to earlier improper repair. In this study, two types of most commonly...
Article
Full-text available
This article presents the results of material characterisation studies conducted on historical clay bricks and binder sampled from the brick masonry gallery of the southern quadrangle of the World Heritage Site of Vat Phou in Champasak, Province of Laos PDR. The primary objective of the sampling was to conduct micro-analytical laboratory investigat...
Conference Paper
When concrete construction is concerned, the most important way to ensure more sustainability is to provide for the desired durability so that material, energy and expenditure is limited for the repair and rehabilitation during the expected service life, in addition to avoiding difficulties caused to the users or inhabitants due to problems that ma...
Article
Full-text available
This paper provides a review of the development of digital fabrication methods in the construction industry and academia, with a major emphasis on extrusion-based 3D printing. A detailed description of the work done by the research group in IIT Madras in developing a Portland cement-based 3D printable formulation is discussed. Finally, the areas in...
Conference Paper
Full-text available
A rational understanding of the physical structure development is essential to distinguish the contribution of supplementary cementitious materials (SCM) in a multicomponent cementitious system. Recently, finely grounded limestone is adopted for co-substitution with SCMs due to synergistic interactions between the three components, i.e., clinker-li...
Conference Paper
In common construction practice, the coating on concrete is usually applied once it is hardened, i.e. after 28 days of hydration, irrespective of the type of polymer and nature of application. However, since the surface characteristics of a cement paste evolve as hydration progresses and hence the interfacial interactions with the polymer change, t...
Article
This paper reports the assessment of rheological characteristics of cementitious pastes prepared with Limestone - Calcined Clay Cement, in comparison with ordinary Portland cement and Portland - Fly Ash cement. The impact on workability retention in concrete is also assessed. Further, a comparison of the performance of different commercially availa...
Article
A rapid and reliable performance test will enable fast and suitable selection of binder for each service environment. In order to evaluate the possibility of using smaller specimens to accelerate the sulphate resistance tests, Portland cement mortar specimens of sizes 20 × 20 × 160 mm, 25 × 25 × 280 mm and 40 × 40 × 160 mm were continuously immerse...
Conference Paper
The buildability of printable concrete signifies the ability of the printed structure to retain the extruded shape and to sustain the dead load of subsequent layers on first extruded layer without collapse. Higher buildability can help in construction of tall sections in minimum possible time. The buildability depends on structural build-up rate wh...
Conference Paper
Stone is a prominent material in the construction industry in all parts of the world. Numerous ancient structures were built with different types of stones ranging from granite, laterite, sand stone, and limestone to coral stone, depending on the corresponding geological setting, climatic conditions and availability of material. The stone masonry s...
Conference Paper
Granite constitutes a large part of the Indian historical monuments- distributed in coastal and non-coastal areas. Among these structures, many are currently with weathering traces and need repair. An efficient restoration required proper understanding of the material and their durability behaviour. The paper investigates the considerable influence...
Article
In this paper, a Helmholtz-potential-based thermodynamic approach was developed for modelling fluids that exhibit both yielding and thixotropic behavior. The yielding behavior was captured using a framework of multiple natural configurations. The thixotropy was described using a structural parameter. The Helmholtz potential is made a function of a...
Article
Extrusion pressure-displacement tests on cementitious pastes with multiple starting materials and differing particle packing, subjected to different extrusion geometries are reported. The steady state extrusion pressure (equivalent to extrusion yield stress) and the deadzone length (static zone of material buildup at die entry) are determined from...
Article
Full-text available
About a decade of research carried out at IIT Madras on cementitious systems has shown that the partial replacement of portland cement with supplementary cementitious materials (SCMs) has benefits as well as limitations. The SCMs do not adversely affect the long-term compressive strength and drying shrinkage of concretes, though there may be some c...
Article
A critical criterion for the extrusion of cementitious materials is that the mix used must remain stable and homogeneous without undergoing phase separation. Therefore, it is important to have an assessment of water retention capacity of mortars to be used for such purposes. Although there are empirical methods like bleed test (ASTM C1741 – 18), th...
Conference Paper
Full-text available
The present study investigates the effect of concrete mixture proportioning on two major performance parameters which include compressive strength and surface resistivity for limestone calcined clay cement (LC3) and FA30 (70% OPC + 30% Class F fly ash) binders. The findings show that there was a significant early strength development of about 38–88...
Article
This paper discusses the role of physical structure alterations on three binder types: plain portland cement, fly ash-based binder and calcined clay-limestone binder. The kinetics of physical structure development and the relevance in transport properties were distinguished using an interlinked parameter in concrete and paste. A systematic experime...
Article
Numerical simulation of chloride diffusion through high-performance binding systems such as limestone-cal-cined clay cement (LC3) and its comparison to control and fly ash modified concretes is discussed. The simulation framework considers the pore structure of concrete, the concentration-dependence of diffusion coefficient, and Freundlich binding....
Article
Full-text available
This paper presents a summary of the major findings from the studies conducted at IIT Madras on Limestone Calcined Clay Cement (LC3), in comparison with plain portland cement and fly ash-based binder. The study attempts to delineate the chemical and physical effects of binder components in LC3 on hydration and hardening, property development, binde...
Article
This paper examines the printability of concrete formulations made using lightweight expanded clay aggregates (LECA) of maximum size 10 mm. The effect of coarse aggregate addition on the two essential aspects of printing, i.e., extrudability and buildability are examined using a piston-pump-based 3D printer system. The extrudability is assessed by...
Article
Full-text available
Information on properties and behavior of the ancient materials is critical in adopting appropriate strategies for preservation of historic monuments. Coral stones are materials with unique physical properties, and is common in ancient stone constructions. But these are not commonly in use in new buildings, and even quarrying of coral stones is ban...
Article
Sugarcane bagasse ash (SCBA), a by-product from sugar industry, has been evidently reported as a potential alternative cementitious material that can partially replace cement. In spite of its high valorization potential in cement production, the large quantity of bagasse ash generated from Indian sugar plants (44,220 tonnes/day) is entirely unutili...
Conference Paper
Full-text available
In the light of the increasing demand for cement in construction and dwindling reserves of cement-grade limestone, the blend of ground limestone and lower grade calcined clay has emerged as a potential candidate for large volume cement replacement. Studies of such ternary blended systems in paste and concrete reveal very interesting physical and ch...
Chapter
Historic lime binders were often modified by the addition of materials con-taining reactive silicates and aluminates. Roman builders utilized volcanic deposits from Pozzuoli near Naples, as the addition of this volcanic ash im-proved the performance of mortar. Pozzolans can be of natural or artificial origin; traditional artificial pozzolans were p...
Conference Paper
Full-text available
In this study, the compositional robustness of limestone-calcined clay combination as clinker replacement in cement, and its effect on concrete performance was assessed in detail. The ratio of limestone-calcined clay in the LC3 with 55% clinker was varied from 1:1.25, 1:2, and 1:3.5 with increasing limestone dosage from 10% to 20%. Additionally, bi...
Article
Full-text available
The article [Title], written by [AuthorNames], was originally published electronically on the publisher’s internet portal (currently SpringerLink) on 3 December 2018 without open access.
Conference Paper
Ordinary Portland cement is not a preferred binder for masonry structures in heritage monuments as it leads to incompatibility with the masonry units, especially in the case of porous brick and stone masonry because of its high strength along with poor resistance to cracking. The preferred binder in the past was lime; however, lime mortars tend to...
Article
Full-text available
This paper reports the characteristics of decorative incised plaster works of New Delhi, from historic monuments belonging to 13th to 16th century C.E. Visual examination of the historic plasterwork depicts that these are made of two layers; a base coat which is coarser in appearance and a finer finishing coat, which is the incised plaster layer. F...
Chapter
Full-text available
Leakage accidents in sodium cooled fast breeder reactors trigger various thermo-chemical degradations of structural materials used for their construction. The interactions of hot liquid sodium with concrete at around 550 °C and above are investigated in this paper. Potential materials were designed and tested. Degradation mechanisms and extend of d...
Article
The current study deals with test methods for characterizing the mechanical behaviour of 3D printed wall elements. At first, the effect of interfaces present in a printed concrete element was examined through an assessment of porosity and bond shear test. The porosity was evaluated using specimens extracted from the bulk as well as from the interfa...
Article
This paper describes a unique international inter-laboratory study on the carbonation resistance of concrete prepared with different supplementary cementing materials. Concrete specimens – from 45 different concrete mixtures – prepared centrally in Lafarge Centre de Recherche (France)were shipped in a sealed condition to 4 other academia research l...
Article
Full-text available
The effects of an operating water head (OWH) and reduced graphene oxide (RGO) addition on the pervious concrete filter (PCF) and heavy metals interaction were investigated in the present study. Five simulated wastewaters containing Cd, Zn, Cu, Pb, and these four ions mixed together were filtered by PCF monoliths, considering the influence of three...
Conference Paper
Fire is a serious natural disaster that can ruin not only the functionality but also the heritage value of ancient monuments. This paper addresses the direct examination of the extent of microcrack formation and mineralogical changes to evaluate the degree of fire damage in a granite structure. The study described in the paper is conducted on a mas...
Conference Paper
The focus of this paper is to discuss the methodology for characterization of lime based materials from historical monuments, with a view to their repair. The case study of the lime mortar samples collected from the grand entrance tower of the Pundarikaksha temple in the southern state of India, Tamil Nadu, is discussed. Most part of the monument i...
Article
Full-text available
Carbonation induced corrosion of the embedded steel reinforcement is a major deterioration mechanism of reinforced concrete structures, mainly in inland/ highway environments of tropical countries. Carbonation leads to uniform reduction in the cross sectional area of steel reinforcement. In general, Supplementary Cementitious Materials (SCMs) can i...
Article
This paper presents data on the chloride diffusion coefficient (Dcl), ageing coefficient (m) and chloride threshold (Clth) related to seven concretes (four M35 and three M50) with OPC, OPC+PFA (pulverized fuel ash) and limestone-calcined clay cement (LC3). Using these, the service lives of a typical bridge pier and girder with the PFA and LC3 concr...
Conference Paper
Recent studies on the binder and concrete properties of limestone calcined clay cement (LC3) have shown good potential for producing high-performance, low clinker cement with a combination of limestone and calcined clay [2]. The greater resistance to ionic ingress, more specifically chloride ingress and sulphates, was found to be strongly influence...
Conference Paper
Full-text available
Various properties of limestone calcined clay cement (LC3) as a binder and those of concretes made with LC3 were assessed during the last four years at IIT Madras to understand its potential as an alternative mainstream cement. LC3 from two major industry-scale productions was used in the evaluation, and the major findings from the research are sum...
Poster
Full-text available
Flyer for major international conference on calcined clays in concrete - 3rd such conference in a successful series...
Chapter
Cementitious materials being highly alkaline in nature are easily attacked by the acids present in industrial effluents, with implications in its mechanical and durability properties. This paper aims to evaluate the degradation kinetics of cement paste when exposed to citric acid solution by performing a static immersion-based-accelerated leaching...
Conference Paper
Brick structures near and on the sea shore can be affected by different salts, mainly chlorides and sulphates. The mechanism of degradation due to the salt attack varies with the initial properties of the brick, type of salt and the conditions prevailing. In the current study, 2 types of bricks were investigated for their physical properties and mi...
Article
Sugarcane and rice are cultivated in vast tracts of land in the Southern part of India. The bagasse and rice husk that are collected during the processing of sugarcane and paddy respectively possess good calorific value and are used for supplementary energy production. However, the ash generated in the process is dumped in landfills. This paper eva...
Article
Studies on understanding the reactivity of alternative materials are typically performed on paste mixtures. This study attempts to explore the contribution of supplementary cementing materials (SCMs) to the properties of blended cementitious mortars. The strength and microstructural development of mortars are investigated through parameters such as...