Link to Latest Report: June 2023 Progress Report
Background:
Polymer concrete overlays are light weight, wear resistant, skid resistant and waterproofing characteristics make them an intelligent and durable decision for new construction, maintenance, rehabilitation and preservation of bridges. A polymer concrete overlay also minimizes traffic disruption. It’s generally applied at a total thickness of only one-half to three-quarter inch. Their rapid cure (open to traffic within 3 hours) characteristic is highly suitable for accelerated bridge construction applications. In some cases, workers can place the overlay at night then open it to traffic the next day. Moreover, these overlays are corrosion resistant, providing a barrier between the dissimilar materials to minimize galvanic corrosion, saving the expense of applying additional corrosion-resistant primers to the steel reinforcement; have very good cracking resistance and have superior durability [1]. When bridge deck overlays are considered, a strong bond to the existing concrete surface and/or reinforcement is required. The properties discussed above make polymer-based materials a favorable material for bridge deck overlays [2] but improving the bond strength of polymer concrete is heavily unexplored and can bring significant benefit in accelerated bridge construction. Polymer-based overlays show no delamination with the substrate concrete beams after 2 million cycles of fatigue loading [3]. It is important for the bonded joint to be able to sustain all expected in-service loads and environmental conditions, which can vary considerably.
Objective:
This project proposes to investigate the bond behavior of polymer concrete for bridge deck overlays modified at the material level using functionalized carbon nanotubes. Over the last fifteen years, researchers have examined the use of nanomaterials to alter a materials’ behavior. The association of CNTs in cementitious composites is well known for improvement of material, elastic, and mechanical properties of cement [4-6]. The incorporation of CNTs in polymer concrete mixes, however, is heavily unexplored and their effect of bond strength of polymer concrete mix has not been investigated. Therefore, the objectives of this research are (a) To assess and compare bond performance of nanomodified polymer overlay systems under laboratory test conditions, (b) To suggest the optimum mix design of CNTs modified polymer concrete suitable for bridge deck overlays and (c) To inform the changes observed in bond strength with the incorporation of three different quantities of CNTs polymer concrete bring for use in bridge deck overlay applications (d) To suggest industry guidelines for effective application of thin polymer overlays to improve safety, and extend service life of bridges.
Scope:
This project focuses on the development of simulation technique targeted at bridge demolition. The following tasks will be performed to achieve the project objective:
- Task 1 – Development of polymer concrete mix design
- The polymer concrete mix in this study will be developed. An extensive literature review will be conducted to obtain an optimum mix of polymer concrete suitable for bridge deck overlays.
- Task 2 – Identification of nanomaterial functionalization for dispersion
- In this task, the most suitable functionalization of 0.5 wt.% and 1 wt.% CNTs content with respect to binder amount is identified for effective nano modification and chemical changes in resin.
- Task 3 – Nano modification process of polymer concrete mix
- Three-roll mill known as a “calendaring” technique is used in this task to achieve good dispersion of the nanomaterials in the polymer matrix
- Task 4 – Evaluation of mechanical properties and bond strength of nano enhanced polymer concrete
- Bond strength tests are performed in accordance with ASTM C1583.
Research Team:
Principal Investigator: Dr. Shreya Vemuganti
Co-Principal Investigator: N/A
Research Assistants: Abdirahman Ahmed Haibe, Ali Akbarpour
Previous Progress Reports: