One of the biggest advantages of Roller Compacted Concrete is faster and economic construction along with lesser heat generation. It is primarily used in mass concrete work like in Pavements, Ports and Dams. In this study the properties of Roller Compacted Concrete such as Vee-Bee density, Vee-Bee time, initial setting time, final setting time and compressive strength are studied for twelve mixes prepared using two types of fly ash sources, three cement sources and three admixture types. Furthermore, on one of the mixes with the least cement to fly ash ratio mechanical and thermal property related tests were performed. These tests include split tensile strength, direct tensile strength, modulus of elasticity, Poisson's ratio, apparent cohesion, angle of internal friction, specific heat of concrete by Transient Plane Source (TPS) method and Coefficient of Thermal expansion of Concrete. From the study it was found that compressive strength at 365 days is nearly two times that of 28 days. Also, there is negligible effect of adding admixture on compressive strength of roller compacted concrete. Current study shows that finer the fly ash, higher the compressive strength at later stage. The study on mechanical and thermal properties of Roller Compacted Concrete indicates that results are in line with Indian Standard Specification and Internationally reported values.

Roller compacted concrete (RCC) is a special concrete having similar ingredients as in the case of conventional concrete, but in different proportions. Use of fly ash to replace significant proportion of Portland cement (PC) for RCC mix is very popular. However, use of limestone in RCC is not so popular. Limestone can act as an inert filler as well as can take part in hydration process and development of different hydration products to a limited extent. The study attempts to determine the optimal replacement levels of PC using fly ash and limestone for development of high volume fly ash based roller compact concrete with limestone filler for use in construction of dams in India by evaluating the fresh properties (in terms of Vee Bee time, density and setting time) and compressive strength (at 7, 28, 56, 90 and 180 days) for different RCC mixes having varying proportions of PC, fly ash and limestone. The study evaluation of 17 RCC mixes prepared by replacing PC to an extent of 72% (by weight of total cementitious content) using two types of fly ash and two types of limestone from different sources to observe the variations in setting time, short and long-term strength for the concrete. For RCC mixes having ternary cementitious systems (combination of OPC, fly ash and limestone), setting time values were observed to be in between setting times of mixes made with binary cementitious systems (i.e. OPC and limestone & OPC and fly ash). Optimum performance in terms of compressive strength at all the ages was observed for mixes with ternary cementitious system due to the synergistic contributions (physical and chemical) of both fly ash and limestone.

Assessment of 28 days strength from accelerated strength (1 day) can be extremely helpful. Early prediction of 28 days compressive strength is required basically for two purposes. First, to finalize the concrete mix proportions in the laboratory and secondly, for quality control purpose during construction. Through this concept designers can easily identify the uncalculated errors during mix design or variations in materials and exposure conditions etc. and take necessary correction and modification measures to attain the desired strengths at 28 days. As per IS: 9013 methodology to predict the 28 days strength of concrete from accelerated cured strength are indicated only for normal/control concrete. In the past few year focus has shifted from Ordinary Portland Cement (OPC) to Portland Pozzolana Cement (PPC). Fly ash is also being used widely at sites as replacement of OPC. However, there is no such guideline available by which the assessment of 28 days strength of Indian fly ash concrete can be made from accelerated strength tests.  In the present study an attempt has been made to predict the expected 28 days compressive strength of concrete having PPC or OPC with fly ash using accelerated temperature regime methods. The experimental study includes the use of 2 brands of PPC, 5 brands of OPC and 2 sources of fly ash for replacement of OPC ranging from 20% to 45 %. Two temperature regimes 900C and 820C were used for accelerated curing. The samples were cured for 7.5 hours and 20hours respectively in each regime for expected 28 day compressive strength. The mathematical equations to estimate the 28 days compressive strength of concrete, cured at 900C for 7.5 hours for mixes having PPC, OPC mixed with fly ash 20% to 35% is fexp28 = 1.223 facs +2.024. The mathematical equations to estimate the 28 days compressive strength of concrete, cured at 900C for 7.5 hours for mixes having PPC, OPC mixed with fly ash more than 35% and up to 45% is fexp28 = 0.993 facs + 6.044.