Radhakrishna G. Pillai

Bio: Radhakrishna G. Pillai is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Corrosion & Cementitious. The author has an hindex of 13, co-authored 58 publications receiving 688 citations. Previous affiliations of Radhakrishna G. Pillai include Texas A&M University & Indian Institutes of Technology.

Sustainability-based decision support framework for choosing concrete mixture proportions

Abstract: A framework is proposed, along with two objective indices, for the selection of concrete mixture proportions based on sustainability criteria. The indices combine energy demand and long-term strength as energy intensity, and carbon emissions and durability parameters as A-indices, which represent the apathy toward these essential features of sustainability. The decision support framework is demonstrated by considering a set of 30 concretes with different binders, including ordinary portland cement (OPC), fly ash, slag and limestone calcined clay cement (LC3). In addition to the experimental data on compressive strength, chloride diffusion and carbonation, life cycle assessment has been performed for the concretes considering typical situations in South India. The most sustainable of the concretes studied here, for service life limited by chloride ingress, are those with LC3, OPC replaced by 50% slag, and ternary blends with 20% each of slag and fly ash. In the case of applications where carbonation is critical, the appropriate concretes are those with OPC replaced by 15–30% slag or 15% fly ash, or with ternary blends having 20% slag and 20% Class F fly ash.

Parameters influencing corrosion and tension capacity of post-tensioning strands

Abstract: A 12-month long strand corrosion test program with 298 specimens was conducted to identify and quantify parameters influencing corrosion and tension capacity of strands in post-tensioned bridges. The parameters investigated were grout class, moisture content, chloride concentration, void type, and stress level. The test specimens were 41 in. (1041 mm) long, in unstressed or stressed conditions, partially or completely embedded in cementitious grout, and exposed to various environmental conditions representing possible field conditions. After the exposure period, the grout material was removed and the strand surfaces were cleaned and visually evaluated for corrosion damage. The tension capacities of the strands were then determined. Results indicate that the corrosion was most severe at or near the grout-air-strand (GAS) interface. Corrosion evaluation and statistical analysis of the strand tension capacity results show that orthogonal, inclined, and bleedwater void conditions caused more corrosion and tension capacity loss than parallel and no-void conditions. The change in grout class did not result in statistically significant changes in the tension capacity of the strand samples evaluated. Statistically significant changes in tension capacity were observed with changes in the GAS interface, stress level, moisture content, and chloride concentration.

Corrosion of steel by concrete

Abstract: The author details the reactions of various concretes on steel reinforcement. Although portland cements, slag cements and high alumina cements are all hydraulic binders, each possess special properties which are examined. The discussion of causes and methods of preventing the corrosion of steel reinforcement covers such aspects as galvanised steel reinforcement, effects of concrete composition, corrosion of steel reinforcments in concrete and prestressed reinforcement. It is concluded that the most significant influences on the corrosion of prestressing wire in concrete are: the presence of chloride; the presence of nitrates; the composition of the concrete; the degree of carbonation of the concrete; concrete compaction and, chlorides and sulphates should be used as far as possible when steel is embedded. (TRRL)

Aramis Or The Love Of Technology

Abstract: Thank you for reading aramis or the love of technology. Maybe you have knowledge that, people have look numerous times for their chosen books like this aramis or the love of technology, but end up in harmful downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they are facing with some infectious bugs inside their computer. aramis or the love of technology is available in our book collection an online access to it is set as public so you can download it instantly. Our books collection spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the aramis or the love of technology is universally compatible with any devices to read.