Date of Defense
17-6-2026 10:00 AM
Location
F1-1117
Document Type
Thesis Defense
Degree Name
Master of Science in Water Resources
College
COE
Department
Civil and Environmental Engineering
First Advisor
Prof. Hilal El-Hassan
Keywords
Concrete, Waste paper ash, Recycled aggregate, Accelerated carbonation curing, CO2 sequestration, Waste valorization.
Abstract
The concrete industry has a considerable environmental impact. The manufacture of ordinary Portland cement (OPC) emits a large amount of carbon dioxide, while the extensive extraction of virgin natural aggregates further burdens the environment during concrete production. This thesis is concerned with the development of low-carbon concrete through the combined utilization of waste paper ash (WPA), recycled aggregates, and accelerated carbonation curing. The main objective is to reduce the environmental footprint of concrete products, including masonry units, by enhancing their carbon sequestration potential, decreasing the use of cement, and alleviating reliance on virgin aggregates, while also maintaining adequate mechanical and durability properties. The experimental program was conducted in three phases. The first phase aimed to optimize key mix design parameters, namely WPA replacement levels, water-to-binder ratio, aggregate-to-binder ratio, and carbonation curing regime, to maximize the CO2 sequestration potential of WPA-OPC blended carbonation-cured concrete without compromising its performance. In this phase, a comprehensive characterization of WPA was carried out by evaluating its chemical and physical properties as well as its microstructure. Additionally, the compressive strength, water absorption, and volume of permeable voids of the WPA-OPC blended carbonation-cured concrete were examined. As an alternate method to reduce the carbon footprint of concrete, the second phase investigated the effect of incorporating different combinations of recycled and carbonated recycled aggregates (i.e., coarse and fine) on the CO2 uptake and compressive strength of carbonation-cured OPC concrete. The goal was to identify the most effective aggregate mixture for superior CO₂ storage and compressive strength of OPC concrete. The final phase adopted the findings of the first two phases to synergically incorporate WPA and recycled aggregates (i.e., carbonated or uncarbonated) as cement and aggregate replacement, respectively, in a two-step carbonation-cured concrete to examine their effect on CO₂ uptake, total CO₂ reduction, compressive strength, water absorption, and the volume of permeable voids. The developed carbonation-cured concrete incorporating WPA and recycled aggregates provides an effective means for reducing the environmental impact of concrete production by enhancing CO₂ sequestration, reducing cement demand, and valorizing waste materials. Accordingly, the developed concrete mixtures support concrete decarbonization efforts and the circular economy while maintaining properties suitable for precast concrete masonry unit applications.
Included in
UTILIZING WASTE PAPER ASH AS PARTIAL CEMENT REPLACEMENT IN CONCRETE
F1-1117
The concrete industry has a considerable environmental impact. The manufacture of ordinary Portland cement (OPC) emits a large amount of carbon dioxide, while the extensive extraction of virgin natural aggregates further burdens the environment during concrete production. This thesis is concerned with the development of low-carbon concrete through the combined utilization of waste paper ash (WPA), recycled aggregates, and accelerated carbonation curing. The main objective is to reduce the environmental footprint of concrete products, including masonry units, by enhancing their carbon sequestration potential, decreasing the use of cement, and alleviating reliance on virgin aggregates, while also maintaining adequate mechanical and durability properties. The experimental program was conducted in three phases. The first phase aimed to optimize key mix design parameters, namely WPA replacement levels, water-to-binder ratio, aggregate-to-binder ratio, and carbonation curing regime, to maximize the CO2 sequestration potential of WPA-OPC blended carbonation-cured concrete without compromising its performance. In this phase, a comprehensive characterization of WPA was carried out by evaluating its chemical and physical properties as well as its microstructure. Additionally, the compressive strength, water absorption, and volume of permeable voids of the WPA-OPC blended carbonation-cured concrete were examined. As an alternate method to reduce the carbon footprint of concrete, the second phase investigated the effect of incorporating different combinations of recycled and carbonated recycled aggregates (i.e., coarse and fine) on the CO2 uptake and compressive strength of carbonation-cured OPC concrete. The goal was to identify the most effective aggregate mixture for superior CO₂ storage and compressive strength of OPC concrete. The final phase adopted the findings of the first two phases to synergically incorporate WPA and recycled aggregates (i.e., carbonated or uncarbonated) as cement and aggregate replacement, respectively, in a two-step carbonation-cured concrete to examine their effect on CO₂ uptake, total CO₂ reduction, compressive strength, water absorption, and the volume of permeable voids. The developed carbonation-cured concrete incorporating WPA and recycled aggregates provides an effective means for reducing the environmental impact of concrete production by enhancing CO₂ sequestration, reducing cement demand, and valorizing waste materials. Accordingly, the developed concrete mixtures support concrete decarbonization efforts and the circular economy while maintaining properties suitable for precast concrete masonry unit applications.