Improved performance of preplaced aggregate concrete with low cement content | |
| Author | Phobprod Pornsirirat |
| Call Number | AIT Thesis no.ST-24-18 |
| Subject(s) | Aggregates (Building materials) Concrete--Additives |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | During the casting of Preplaced Aggregate Concrete (PAC), coarse aggregates are initially preplaced into the formwork, and then grouts are added to fill in the voids left by the coarse aggregates. Coarse aggregates can now occupy a far bigger volume than they could with traditional casting techniques. This technique primarily depends on the grout's capacity to fill voids and the size of those voids, both of which depend on the workability of the grout and the form and gradation of the coarse aggregate.This research study intended to improve the mechanical strength and performance of Preplaced Aggregate Concrete with low cement content while maintaining its overall properties. The purpose of this work is to create the optimal mix of PAC with low cement content that can be utilized for specific applications. In order to lower the void content, a larger size of fine aggregates is also added into the mold in addition to coarse aggregates, which helps reducing the void content. For further reduction of cement content, supplementary cementitious materials (SCMs) like fly ash (30 to 40%) and silica fume (7.5%) are used into the grout. Four-factor two-level full factorial design is setup using Design of Experiment to study the effects of sCMs in PAC. Compressive strength of 43.47 MPa and Flexural strength of 4.93 MPa were the highest value achieved at 28 days. For the maximum replacement of cement with high water to binder ratio and superplasticizer dosage, the compressive strength and flexural strength were 24.04 MPa and 4.23 MPa respectively. Additionally, all the mixes underwent tests for rapid chloride penetration, abrasion, and water permeability, with an excellent outcome. With fixed ratio SF/B of 0.075, fly ash to binder ratio and superplasticizer dosage impact all responses, which influence flowability, mechanical strength, and durability properties. |
| Year | 2024 |
| Type | Thesis |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Krishna, Chaitanya;Thanakorn Pheeraphan (Co-chairperson) |
| Examination Committee(s) | Raktipong Sahamitmongkol;Punchet Thammarak |
| Scholarship Donor(s) | GMS Scholarships |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2024 |