01/04/2021: New Team Member
Welcome Ishrat Baki Borno! A new graduate student in our team. She will work on the development of high-performance CO2 cured cementitious materials.
11/05/2020: New Research Article Published
This study investigated the potential application of three types of CNF for enhancing the performance of ordinary Portland cement (OPC) pastes: pure CNF (PCNF), silica coated CNF (SCNF), and lignin-containing CNF (LCNF). The better stability of SCNF also resulted in improved workability of the cement paste mixtures containing this type of cellulose. The addition of 0.1% SCNF increased the compressive strength (90 days) by 13% when compared with the control batch and 10% compared with the PCNF batch. The addition of 0.1% of PCNF enhanced the flexural strength by 70% followed by LCNF with 40% improvement.
09/11/2020: Dr. Ashraf wins DARPA Young Faculty Award
Warda Ashraf has received a Defense Advanced Research Projects Agency (DARPA) Young Faculty Award (YFA) to fund her research. Her two-year, $495,465 project, “Recreated Roman Concrete using Alkali-Activated Calcined Clays,” could be extended up to $1 million and three years.The goal of this project is to mimic the ancient Roman Concrete to produce highly durable and resilient construction material. Learn more here:
09/24/2020: New Research Article Published
This article presents an investigation on the reactivity of ground and sieved bio ash that can be used as alternative sources of SCM. The oxide contents of bio ash are similar to Class-C coal fly ash. Accordingly, bio ash was found to have both hydraulic and pozzolanic reactivity. Grinding the bio ash improved its pozzolanic reactivity by 25% as per the modified Chapelle test. Using bio ash as SCM was also found to increase the ettringite formation in cement matrix. Nevertheless, the potential of excessive expansion of the paste samples due to the ettringite formation was found to be negligible.
08/28/2020: New Research Article Published
In this work, the effects of cellulose nanofibrils (CNFs) on workability, hydration reaction, microstructure, early age shrinkage, fracture properties, flexural strength, and compressive strength of cement paste were investigated. Because of their hydrophilicity, CNFs retain water and work as reservoirs (internal curing), which explains the improvement in properties at low w/c ratios. Significant increases in fracture energy (up to 60%) and flexural strength (up to 116%) suggest that CNFs are an effective toughening mechanism, acting as bridges that increase the energy required for crack propagation.
07/10/2020: Research Grant from National Science Foundation (NSF)
Dr. Ashraf received a $491,968 multi-disciplinary grant as PI from NSF. The goal of this project Interaction Between Carbon Dioxide and Cementitious Materials Using Biomimetic Molecules. This research aims to make sustainable infrastructure materials, including supplementary cementitious materials (SCMs) and alkali-activated materials (AAM), last longer by reducing their deterioration when these are exposed to carbon dioxide. This research will further contribute to the low-carbon future by advancing the understanding and applications of cementitious materials that can directly serve as carbon dioxide sinks.