An experimental study of sprayed motar for repairing application | |
| Author | Siriporn Thongjaeng |
| Call Number | AIT Thesis no.ST-15-03 |
| Subject(s) | Concrete--Shrinkage Reinforced concrete--Cracking |
| Note | A thesis submitted in partial fulfillment of the requirements for thedegree of Master of Engineering inStructural Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. ST-15-03 |
| Abstract | The objective of this researchis to develop the mix proportion of sprayed mortar by using fly ash and to investigate the performance of sprayed mortar regarding fresh and hardened properties, including slump flow, setting time, sagging, build-up thickness, compressive strength, bond strength, drying shrinkage and age at cracking for repairing application. The researchfocused on the maximum size of aggregate of 0.6 mm. with the addition of admixtures and the percentage of fly ash replacement. The results have shown that sprayed mortar with 0.01% Starch ether (polysaccharide compound), 0.5% Mighty Mx (water reducing agent) and 8% Sika Grout-Aid (shrinkage compensating admixture) is the optimum mix proportion for use to replace with fly ash. The maximum build-up thickness of each layer is50 mm. that can be applied without sloughing. The replacement of 40 percent fly ash alsoproduced satisfactory performance which included workability, pumpability and sprayability. The 28 days compressive strength, 28 days bond strength, drying shrinkage and age at cracking of this mix were 38 MPa, 1.81 MPa, no shrinkage at 28 days and no cracking at 60 daysrespective. The hardened performance was higher when sprayed compared with hand application. On the other hand, this sprayed mortar can be applied to repair of damaged column. After repairing, ultrasonic pulse velocity (UPV) was used to check a quality of concrete. The result shown that the quality of concrete was good. In addition, the cost of this sprayed mortar was lower than commercial product with similar properties and application. The cost saving is 97.6 % which compared with the cheapest commercial product. Therefore, the development of sprayed mortar with fly ash replacement hasbeen effective with high performance and low cost in repairing application. |
| Year | 2015 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. ST-15-03 |
| 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) | Pennung Warnitchai, |
| Examination Committee(s) | Thanakorn Pheeraphan;Punchet Thammarak |
| Scholarship Donor(s) | Thailand (HM King) |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2015 |