EXPERIMENTAL INVESTIGATION ON INTERFACE BOND STRENGTH OF WHITE-TOPPED PAVEMENTS USING DIFFERENT SURFACE PREPARATION TECHNIQUES

1.      The physical properties of cement, fine aggregate, coarse aggregate, fly ash, GGBS, and alkaline activators satisfied the relevant Indian Standards and were found suitable for preparing PQC, RCC, and GPC mixes. 2.      The developed mix proportions for PQC, RCC, and GPC produced concrete with satisfactory workability and strength suitable for rigid pavement applications. 3.      The workability tests indicated that PQC and GPC exhibited adequate consistency for placement, while RCC showed the expected zero-slump behaviour suitable for roller compaction. 4.      The compressive strength of all concrete mixes increased with curing age, demonstrating continuous strength development. The GPC mix achieved the highest compressive strength among the three individual concrete mixes. 5.      The split tensile strength results indicated that the incorporation of geopolymer binder improved the tensile resistance of concrete, whereas RCC provided adequate tensile strength for use as the structural bottom layer. 6.      The flexural strength of both two-lift concrete systems satisfied the requirements for rigid pavement applications. The GPC–PQC combination exhibited slightly higher flexural strength than the RCC–PQC combination. 7.      The RCC–PQC two-lift pavement demonstrated satisfactory structural performance and can be considered a cost-effective alternative to conventional full-depth Pavement Quality Concrete. 8.      The GPC–PQC two-lift pavement exhibited excellent mechanical performance while reducing the use of Ordinary Portland Cement, thereby improving the sustainability of rigid pavement construction. 9.      The comparative evaluation showed that both RCC–PQC and GPC–PQC systems performed comparably to conventional PQC pavement, indicating that the use of alternative bottom-lift materials does not adversely affect overall pavement performance. 10.   The use of industrial by-products such as fly ash and GGBS in geopolymer concrete contributes to the conservation of natural resources and reduction of carbon emissions associated with cement production. 11.   Based on the overall laboratory investigation, the GPC–PQC combination may be considered the preferred sustainable option where environmental benefits are prioritized, whereas the RCC–PQC combination provides an economical solution for projects emphasizing construction cost and rapid execution. 12.   The results demonstrate that two-lift concrete pavement is a technically feasible approach for rigid pavement construction and has the potential to improve resource efficiency without compromising structural performance.

[1] Indian Roads Congress, Guidelines for Cement Concrete Mix Design for Pavements, IRC:44-2017, New Delhi, India, 2017. [2] Indian Roads Congress, Standard Specifications and Code of Practice for Construction of Concrete Roads, IRC:15-2017, New Delhi, India, 2017. [3] Bureau of Indian Standards, Concrete Mix Proportioning – Guidelines, IS 10262:2019, New Delhi, India, 2019. [4] Bureau of Indian Standards, Plain and Reinforced Concrete – Code of Practice, IS 456:2000, New Delhi, India, 2000. [5] Bureau of Indian Standards, Methods of Tests for Strength of Concrete, IS 516 (Part 1):2021, New Delhi, India, 2021. [6] Bureau of Indian Standards, Splitting Tensile Strength of Concrete – Test Method, IS 5816:1999, New Delhi, India, 1999. [7] Bureau of Indian Standards, Methods of Test for Aggregates for Concrete, IS 2386 (Parts I–IV), New Delhi, India. [8] Bureau of Indian Standards, Ordinary Portland Cement, 53 Grade – Specification, IS 12269:2013, New Delhi, India, 2013. [9] Bureau of Indian Standards, Pulverized Fuel Ash – Specification, Part 1: For Use as Pozzolana in Cement, Cement Mortar and Concrete, IS 3812 (Part 1):2013, New Delhi, India, 2013. [10] Bureau of Indian Standards, Ground Granulated Blast Furnace Slag for Use in Cement, Mortar and Concrete – Specification, IS 16714:2018, New Delhi, India, 2018.