Indian Concrete Journal

100 Years of concrete materials science Bishwajit Bhattacharjee

Concrete materials science originated with Abrams’ pioneering work and its evolution toward modern concrete composite is briefly discussed at the outset. Some research work, carried out at IIT Delhi, are presented. Key topics include a re-examination of Abrams’ Law, thermal conductivity of concrete, durability, and service life of concrete structural elements and sustainability related research. Lastly, the perceived knowledge gaps and way forward are highlighted elaborating opportunities for contemporary and near-future research.

Rational mixture design methods for special concrete-lessons from 2 decades of research at IIT Madras Manu Santhanam

Over the last two decades, IIT Madras has been actively working on different types of special concrete, including High performance concrete, self compacting concrete, fibre reinforced concrete, high density concrete, roller compacted concrete and 3D printed concrete. The complex nature of mixture design to achieve the fresh and hardened state properties necessitates the adoption of systematic procedures that address the key criteria of particle packing and rheology. The experience at IIT Madras indicates that following a rational approach makes it possible to satisfy the fresh and hardened characteristics across a range of workabilities and strengths, also accounting for a change in material types and characteristics. Further, the design process also ensures the attainment of durability when suitable supplementary materials are used. This paper focuses on high strength concrete, high density concrete, self compacting concrete and 3D printed concrete as examples of utilization of this approach.

Era from pozzolanic to super pozzolanic materials: The science behind the inclusion of nano silica in the cementitious composites Biibhuti Bhusan Das

Over the past decade, development in nanotechnology has opened up avenues for the use of nano-additives in the field of construction. This nano-additives incorporation in concrete exhibit significant improvement in the properties and performance, the problem of lower initial strength gain was mitigated and “high performance concrete” could be produced with a superior service life, owing to their reduced size from micro to nano-scale and hence the increased surface area, surface energy, reactivity and surface morphology. Amongst all the nano-additives, nano-silica is found to be the first nano product that replaced the micro silica or silica fume in concrete and it is the most predominantly used nano particle amid all other nano particles in cementitious system. In this regard, understanding the primitive concepts of cement and concrete at the level of nano i.e. hydrate phases of cement to figure out the mechanism of nano-particle addition in concrete. Further, it requires understanding the potentiality of nanosilica in making the concrete durable and environmentally sustainable. Considering this into consideration, a detailed and comprehensive article is presented here describing the chemistry that takes place with the inclusion of nano-silica in the cementitious system.

Research contributions of national council for cement and building materials in the research-driven evolution of Indian Standards P. N. Ojha

This manuscript presents the fundamental and blue-sky research contributions of the Construction Development and Research Group at the National Council for Cement and Building Materials (NCCBM). The research spans the development of alternative aggregates from construction and demolition (C&D) waste and industrial by-products such as bottom ash, ferrochrome slag, electric arc furnace slag, conarc slag, air cooled blast furnace slag, granulated blast furnace slag etc.; advances in low carbon binders such as fly ash-slag composite cement, Portland limestone cement, high volume fly ash cement, PSC blended with granulated blast furnace slag (GBFS) and LD slag, and fly ash-limestone composite cements etc.; characterization of high-performance concretes (HPC), ultra high performance concrete (UHPC), geopolymer concrete, roller compacted concrete, sintered fly ash lightweight concrete, pervious concrete, plastic concrete and controlled low strength materials and pioneering work in chemical admixture and reinforcement corrosion inhibitor evaluation, thermal studies and temperature control of mass concrete, cathodic protection, 3D printable concrete, etc. The group’s scientific outputs have directly contributed to revisions and formulation of major Indian Standards such as IS: 456, IS: 383, IS: 516, IS: 1199, IS: 9103, IS: 2386^[1-6] etc. This article synthesizes the principal research findings, methodologies, and theoretical advancements developed over the last 10 years of research.