1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Title:	Early age shrinkage cracking, stresses development and creep in restrained ternary geopolymer mortars
Authors:	Ali Mohamed Ali Aboshia (P64800)
Supervisor:	Riza Atiq Abdullah O.K. Rahmat, Prof. Dato' Ir. Dr.
Keywords:	Mortar Polymer-impregnated mortar Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	14-Nov-2018
Description:	Cracking at an early age can be a significant problem especially in conventional concrete pavements, which are restrained or prevented from shrinkage freely. Although pavements cracking can be ascribed to various causes, drying shrinkage cracking is considered the main contributor. Thence, geopolymer binders can be used as the alternative to cement binders. The present study selects three industrial materials, i.e. Metakaolin (MK), Slag (S) and Palm Oil Fuel Ash (POFA) to be utilized as a ternary geopolymer binder known as MKSP with the aim of resolving early age cracking issues. MKSP binder was activated with an alkaline mixture of a sodium silicate (Na2SiO3) solution and ten molar of sodium hydroxide (NaOH) solution in a mass ratio of 2.5. Seven mixes with different ratios of MKSP materials were used to produce MKSP mortars that were selected based on experimental trials. Depending on the amount of the superplasticizer used, the water-to-binder ratio of the mortars was kept at 0.4 and 0.5 ratios. The mortar strengths properties tests were heat-cured for two hours at 80°C and the mortar dry shrinkage tests were cured in room temperature at 23°C and 55% humidity. Tests were performed on the MKSP mortars to determine their compressive strength and strengths properties. ASTM restrained ring test was conducted to determine the role of drying shrinkage, stresses development and creep relaxation on cracking of restrained MKSP mortars at early ages. The mortars were then characterized using X-ray diffraction (XRD), Fourier Transforms Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Results showed that MKSP7 (40% MK, 50% Slag and 10% POFA) sample achieved the highest compressive strength (54MPa) and creep (1.6 MPa) at 28 days (with 7 days age of cracking), and dry shrinkage strain (-149 𝝁ε). Although MKSP6 (40% MK, 40% Slag and 20% POFA) achieved compressive strength (52 MPa) and creep (3.6 MPa) at 28 days (with 18 days age of cracking), and dry shrinkage strain (-154 𝝁ε). In addition, the results of XRD, SEM and FTIR analyses indicated MKSP mortars primarily consisted of 70% crystalline (Si + Al) phase and 30% amorphous (Si + Ca) phase, which implied a high interaction between the ternary materials binder. Therefore, the ternary geopolymer binders can be used to produce MKSP geopolymer concrete with grade 55 MPa and less potential of cracking as alternative to traditional cement concrete with 45 MPa and high potential of cracking at early ages.,Ph.D.
Pages:	185
Call Number:	TA436.A246 2018 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.