Timothy Aiken


School of Planning Architecture and Civil Engineering
David Keir Building, Stranmillis Rd., BT9 5AG
Room OG.312A
Tel  028 9097 4027


MSc in Environmental Engineering (2014) Queen’s University Belfast

BEng in Civil Engineering (2012) Queen’s University Belfast

Professional qualifications



Masud Dornan Travel Scholarship (2015)

STEM Performance Scholarship (2009)

PhD Title

Durability and Microstructural Properties of Geopolymer Concrete

PhD project Description

This project aims to develop understanding of the durability and microstructural properties of cementless geopolymer materials. A cementless geopolymer material is a concrete produced when a replacement product for cement is used. The replacement material is usually blended from different sources which have different chemical and mineral compositions. The sources are usually waste products from other industries, one significant advantage this has over a traditional cement based concrete is the reduced environmental impact. The extraction and production of cement results in a large carbon footprint for concrete, which is significantly reduced when a cementless geopolymer material is used as a replacement product.

The project objectives will be achieved by performing various durability tests on samples of geopolymer and Portland cement concrete in order to compare their performance. The microstructure will also be studied to establish the effect certain durability tests have on the microstructure of geopolymer concrete. These investigations will build upon work already carried out by the Geopolymer team at Queen’s University Belfast. This work amongst many other investigations involved the optimisation of geopolymer mixes in terms of binder composition and activator dosages etc. to achieve concrete mixes with optimum compressive strength and workability. It is the plan within this project to use these optimised mixes for durability assessment, with limited further optimisation when necessary. The durability assessment will include assessment of geopolymer concrete in comparison with Portland cement concrete in terms of acid resistance, sulphate resistance and resistance to changes in climatic conditions namely freeze-thaw and wet-dry cycles. The effects of these attacks on the concrete microstructure will also be assessed to determine the mechanism of deterioration in each condition. The project will also involve characterisation of the various concretes produced using x-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. XRD will be used to quantify what minerals and materials are present in the concretes and SEM will identity the distribution of the minerals and allow quantification of the grain sizes and shapes. It will also be important to characterize the starting materials used and the interaction between the geopolymer cement and various aggregates.


Prof. Wei Sha & Prof. Marios Soutsos



Poster(s)/ Presentation(s)



Silage effluent resistance of geopolymer concrete, effect of freeze-thaw attack on geopolymer concrete and microstructural properties of geopolymer concrete.