This study investigated the effects of waste ceramic powder on both the mechanical and microstructural properties of mortar. The study explored the utilization of $$\hbox {Al}_{2}\hbox {O}_{3}$$
 –
 $$\hbox {SiO}_{2}$$
 nanoparticles in mortar as cement replacement. Four mixes containing ceramic nanoparticles (0, 20, 40, and 60%) were prepared. The mortar specimens were tested for compressive strength. The role of ceramic waste powder was investigated through the analysis of microstructure in terms of scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential thermal analysis. The results revealed that the replacement of $$\hbox {Al}_{2}\hbox {O}_{3}$$
 –
 $$\hbox {SiO}_{2}$$
 nanoparticles to the mortar matrix had significantly enhanced the compressive strength. At 90 days, the compressive strength was in the range of 44.7–58.8 MPa. The results were validated through a microstructure test. The mortar with 40% of ceramic replacement showed better performance in terms of C-S-H production from active siliceous containing excessive calcium hydroxide content.

Microstructure and Strength Properties of Mortar Containing Waste Ceramic Nanoparticles

Sustainability assessment, potentials and challenges of 3D printed concrete structures: A systematic review for built environmental applications

Recycling of industrial and agricultural wastes as alternative coarse aggregates: A step towards cleaner production of concrete

The rheological, fresh and strength effects of cold-bonded geopolymer made with metakaolin and slag for grouting

Physical properties, strength, and impurities stability of phosphogypsum-based cold-bonded aggregates

The present investigation is to identify an optimum mix combination amongst 28 different types of artificial lightweight aggregates by pelletization method with aggregate properties. Artificial aggregates with different combinations were manufactured from fly ash, cement, hydrated lime, ground granulated blast furnace slag (GGBFS), silica fume, metakaolin, sodium bentonite and calcium bentonite, at a standard 17 minutes pelletization time, with 28% of water content on a weight basis. Further, the artificial aggregates were air-dried for 24 hours, followed by hardening through the cold-bonding (water curing) process for 28 days and then testing with different physical and mechanical properties. The results found the lowest impact strength value of 16.5% with a cement-hydrated lime (FCH) mix combination. Moreover, the lowest water absorption of 16.5% and highest individual pellet crushing strength of 36.7 MPa for 12 mm aggregate with a hydrated lime-GGBFS (FHG) mix combination. The results, attained from different binder materials, could be helpful for manufacturing high strength artificial aggregates.

Effect of different binders on cold-bonded artificial lightweight aggregate properties

The concrete manufactured by using geopolymer technology is considered to be sustainable and economical. The production of geopolymer concrete helps in converting industrial by-product materials into a valuable product. Compared to OPC concrete, geopolymer concrete has superior strength properties. The advantage of using geopolymer concrete is that it is environment-friendly, has low production cost and protects the available natural resources by utilizing industrial by-products and consuming less embodied energy. The ternary blended, low-molarity (2M) geopolymer concrete is manufactured using fly ash, ground granulated blast furnace slag and alccofine, with M-sand as fine aggregate. The present study aimed to find the optimum ratio of Na2SiO3 to NaOH of geopolymer concrete based on the strength and microstructural characterization through scanning electron microscopy/energy-dispersive X-ray spectroscopy, X-ray powder diffraction, Fourier-transform infrared spectroscopy, kinetic ratios and thermogravimetric analysis/differential scanning calorimetry. The results revealed that the Na2SiO3-to-NaOH ratio of 1.5 had a significant increase in the polymerization of geopolymer concrete, which, in turn, resulted in better compressive strength and microstructural features than the other ratios. Although the results of the study are encouraging regarding the use of ternary blended geopolymer concrete by effective utilization of industrial waste products through an environment-friendly route, they also provide a sustainable and economical route for handling the industrial by-products currently generated in various countries. Additionally, it was found that the use of low molarity (2M) and Na2SiO3-to-NaOH ratio of 1.5 reduced the risk involved in handling the alkaline solution.

Experimental and microstructural assessment of ternary blended geopolymer concrete with different Na2SiO3-to-NaOH volume ratios

High‐temperature sodium‐sulfur battery (HT Na–S) technology has attracted substantial interest in the stationary energy storage sector due to its low cost and high energy density. However, the currently used solid electrolyte (ß‐alumina) is expensive and can only be operated at high temperatures, which compromises safety. On the other hand, liquid electrolytes in room temperature sodium‐sulfur batteries (RT Na–S) are susceptible to dendrite formation and polysulfide shuttle. Consequently, an electrolyte with both solid (shuttle blocking) and liquid (ionic conductivity) properties to overcome the above‐mentioned issues is highly desired. Herein, a high‐performance quasi‐solid state crosslinked gel polymer electrolyte (GPE) prepared in situ using pentaerythritol triacrylate (PETA) exhibiting high ionic conductivity of 2.33 mS cm−1 at 25 °C is presented. The GPE‐based electrolyte shows high stability resulting in a high discharge capacity of >600 mAh gs−1 after 2500 cycles with an average Coulombic efficiency of 99.91%. Density functional theory calculations reveal a weak interaction between the Na+ ions and the oxygen molecules of the PETA moiety, which leads to a facile cation movement. The crosslinked polymer network is tightly connected to the cathode and can confine sulfides, thereby facilitating the conversion process.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/adfm.202201191

Stable Cycling of Room‐Temperature Sodium‐Sulfur Batteries Based on an In Situ Crosslinked Gel Polymer Electrolyte

An experimental study was conducted on high volume fly ash concrete (HVFA) with a constant binder content of 603.2 kg/m3 to investigate the effect of ASTM class C and class F fly ash in concrete. A constant binder content was maintained with a replacement of cement by mass of 20, 40 and 60% using both types of fly ash. The curing was done for 28, 56, 90 and 365 days. The different types of curing systems such as Accelerated curing, Warm water curing, Alternate wet & dry curing along with normal curing were done and the results were compared. Early age testing of concrete (accelerated curing and warm water curing) was conducted to predict the later age strength of concrete. Based on this relationship, the polynomial regression analysis was carried out and coefficients were proposed to find the 28, 56, 90 and 365 days strength of the HVFA concrete.

Regression Models for Prediction of Compressive Strength of High Volume Fly Ash (HVFA) Concrete

Flyash, ground granulated blast-furnace slag (GGBFS) and Alccofine are industrial byproduct materials and require large area of land for the safe disposal. These byproducts which are rich in alumina and silica can be value added, by using as binder in geopolymer concrete. The industrial byproducts are activated by NaOH- or KOH-based alkaline solution. Effective utilization of industrial byproducts in the construction industry will reduce the impact on the environment, which is caused due to ordinary portland cement (OPC). Previous studies on geopolymer concrete are at high molarity of NaOH and curing adopted is hot air oven curing for the effective polymerization of binder material and the alkaline activator solution (AAS). The present study is aimed to understand the effect of Alccofine as a ternary binder in geopolymer concrete at low molarities of NaOH-based alkaline solution under ambient temperature curing. Flyash, GGBFS, and Alccofine are the binder materials considered in geopolymer concrete by complete replacement of OPC. The ratio of Na2SiO3 to NaOH is fixed at 2.5 for all the geopolymer concrete mixes. Msand is used as fine aggregate by replacing with river sand in geopolymer concrete. The study also focused on comparing the compressive strength, split tensile strength, flexural strength, and cost analysis of ternary blended geopolymer concrete with conventional concrete of M30 grade. It is observed from the results that the geopolymer concrete has attained better strength properties than OPC concrete at the lesser cost and the impact on environment is reduced.

S. Bala Murugan

Papers

Effect of different binders on cold-bonded artificial lightweight aggregate properties

Experimental and microstructural assessment of ternary blended geopolymer concrete with different Na2SiO3-to-NaOH volume ratios

Stable Cycling of Room‐Temperature Sodium‐Sulfur Batteries Based on an In Situ Crosslinked Gel Polymer Electrolyte

Regression Models for Prediction of Compressive Strength of High Volume Fly Ash (HVFA) Concrete

A Study on Strength Properties and Cost Analysis of Industrial Byproduct-Based Ternary Blended Geopolymer Concrete