Current state of K-based geopolymer cements cured at ambient temperature

Abstract

The increasing focus on global climate change, the public and consumer preferences for “green” products and the associated markets in carbon credits have promoted the use of alternate cements in place of pure Portland cement binders. Using alkali activation method, waste materials such as fly ash and slag can be modified to replace ordinary Portland cement. In the present study, a combination of sodium hydroxide pellets and sodium silicate solution is used for the alkali activation of fly ash to prepare geopolymer cement. In the same way, a mixture of KOH (pellets) and K-silicate solution has been used with fly ash and slag (used in British Columbia, Canada) for comparison. Ambient temperature curing has been considered in addition to oven curing. Compressive strength tests indicate that both duration and intensity of the temperature affect the properties of the geopolymer. Higher intensity of the temperature accelerates the polymerization process much faster and gives higher compressive strength for the same duration of curing. On the other hand, longer duration of curing leads to improved hardened properties compared to shorter span at the same intensity. This paper presents data for curing done at ambient temperatures and the effectiveness of using potassium- and sodium-based solutions for geopolymer cement. Further recommendations for future work are also included.

Novel Integration of Geopolymer Pavers, Silva Cells and Poplar Trees for In-Situ Treatment of Car-Wash Wastewater

“…The unique manufacturing process of these GC pavers includes using fly-ash and bottom ash, collected from waste produced in thermal power plants, then mixing it with sodium, Na-based polymers and curing at a higher temperature to attain strength and desired durability. The detailed process of producing GC pavers as well as their utility in real-applications can be found in [20][21][22]. Based on these findings [20][21][22], trial batches of Na-based Geopolymer concrete paver blocks (with mold of 150 × 150 × 100 mm) were manufactured and cured at 80 • C, at Lovely Professional University, India.…”

“…The detailed process of producing GC pavers as well as their utility in real-applications can be found in [20][21][22]. Based on these findings [20][21][22], trial batches of Na-based Geopolymer concrete paver blocks (with mold of 150 × 150 × 100 mm) were manufactured and cured at 80 • C, at Lovely Professional University, India. The strong and durable pavers obtained from the lab allowed the researchers to purchase 400 fly-ash based paver blocks casted in a commercial facility.…”

Bayesian Regularized Artificial Neural Network Model to Predict Strength Characteristics of Fly-Ash and Bottom-Ash Based Geopolymer Concrete

“…The specifications of geopolymer concrete represented by i 1 , i 2 , …, i 11 are considered as eleven input features in the input layer of the network. Even though the features are quite commonly used in the context of geopolymer concrete, further details about what these features mean is reported in the literature [ 43 , 44 ]. This is not described here in order to maintain brevity.…”

Editorial

“…Rishi Gupta of the Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia, Canada and Harsh M. Rathod of the Institute of Technology, Nirma University, Ahmedabad, Gujarat, India, report their studies 14 on 'Current state of K-based geopolymer cements cured at ambient temperature'. The increasing focus on global climate change, the public and consumer preferences for 'green' products and the associated markets in carbon credits have promoted the use of alternate cements in place of pure Portland cement binders.…”