A. S. Santhi

Bio: A. S. Santhi is an academic researcher from VIT University. The author has contributed to research in topics: Fly ash & Compressive strength. The author has an hindex of 9, co-authored 21 publications receiving 207 citations. Previous affiliations of A. S. Santhi include A.V.V.M Sri Pushpam College.

Effect of cold bonded fly ash aggregates on strength & restrained shrinkage properties of concrete

Abstract: Concrete is a mixture of cement, fine and coarse aggregates, in which aggregates occupy the major volume. Also, the strength of concrete varies with the type of aggregate used. In Recent days, the scarcity of aggregates due to the massive development in infrastructure field made the researchers think about an alternate source of concrete materials. Economical and environment friendly way is to consider the usage of industrial waste as a substitute material. Fly ash is already studied in a mammoth level for its potential to be used as a cement replacement material. Here in this study, the feasibility of usage of coarse aggregate made of fly ash is studied for its restrained shrinkage property in concrete. For the purpose of experimentation concrete mixes are designed for M40 grade by 30%, 60% and 100% replacement of natural gravel to fly ash aggregates as coarse aggregates in concrete. Compressive strength, Rise in temperature and plastic shrinkage tests are conducted to study the strength and restrained shrinkage property of concrete using fly ash aggregates and the results are compared with that of concrete with natural gravel.

Statistical model to predict the mechanical properties of binary and ternary blended concrete using regression analysis

Abstract: This research paper presents the use of wasteful supplementary cementitious materials like fly ash and silica fume to conserve the cement used in concrete. The cement industry is one of the major producers of greenhouse gases and an energy user. In this study, Portland cement was used as a basic cementitious material. Fly ash and silica fume were used as the cement replacements by weight. The replacement levels of fly ash were 30%, 40% and 50%, and silica fume were 6% and 10%. The water binder ratio was kept constant as 0.4 and super plasticizer was added based on the required workability. Results of the binary and ternary concrete mixtures compressive strength, split tensile strength and flexural tensile strength were taken for studyup to 90 days. Based on the experimental results of compressive strength, prediction models were developed using regression analysis and coefficients were proposed to find the split tensile strength and flexural strength of binary-ternary concrete mixtures at 28 and 90 days.

Regression Models for Prediction of Compressive Strength of High Volume Fly Ash (HVFA) Concrete

Abstract: An experimental study was conducted on high volume fly ash concrete (HVFA) with a constant binder content of 603.2 kg/m3 to investigate the effect of ASTM class C and class F fly ash in concrete. A constant binder content was maintained with a replacement of cement by mass of 20, 40 and 60% using both types of fly ash. The curing was done for 28, 56, 90 and 365 days. The different types of curing systems such as Accelerated curing, Warm water curing, Alternate wet & dry curing along with normal curing were done and the results were compared. Early age testing of concrete (accelerated curing and warm water curing) was conducted to predict the later age strength of concrete. Based on this relationship, the polynomial regression analysis was carried out and coefficients were proposed to find the 28, 56, 90 and 365 days strength of the HVFA concrete.

Investigation of Shear Stud Performance in Flat Plate Using Finite Element Analysis

Abstract: Three types of shear stud arrangement, respectively featuring an orthogonal, a radial and a critical perimeter pattern, were evaluated numerically. A numerical investigation was conducted using the finite element software ABAQUS to evaluate their ability to resist punching shear in a flat plate. The finite element analysis here is an application of the nonlinear analysis of reinforced concrete structures using three-dimensional solid finite elements. The nonlinear characteristics of concrete were achieved by employing the concrete damaged plasticity model in the finite element program. Transverse shear stress was evaluated using finite element analysis in terms of shear stress distribution for flat plate with and without shear stud reinforcement. The model predicted that shear studs placed along the critical perimeter are more effective compared to orthogonal and radial patterns.

A self-reinforced cementitious composite for building-scale 3D printing

Abstract: A design scheme for self-reinforced cementitious composites to be used for building-scale 3D printing processes is introduced. The design is based on that of engineered cementitious composites, which include dispersed short polymer fibers to generate robust tensile strain-hardening. The mechanical property profile of these printable ECC materials is meant to eliminate the need for steel reinforcement in printed structures, providing more freedom and efficiency for building-scale 3D printing processes. The fresh state rheological properties have been systematically manipulated to allow printability. Effects on fresh state workability of several compositional ingredients and processing parameters are investigated herein. To maintain consistent printing performance with a batch mixing approach, thixotropy in the fresh state is exploited to temporarily decouple hardening behavior from the processing timeline. Minimal workability loss under continued shear agitation is achieved. Mechanical properties of the printable materials are characterized and the printability of the materials is demonstrated.