The effect of graphene oxide on the mechanical properties, impermeability and corrosion resistance of cement mortar containing mineral admixtures

Graphene oxide (GO) has been found to be an attractive nanomaterial to improve the properties of cementitious composites. However, the use of GO in the industry is limited by its high cost. To achieve a higher cost/performance ratio, GO can be strategically applied in certain parts of cementitious composites structure according to the principle of functionally graded materials. In this study, graded distribution of GO in cement mortar was achieved by sequentially casting a fresh GO-incorporated cement layer on another cement mortar layer. The mechanical properties, especially flexural strength, of layered cement mortar were found to be dependent on the GO content, the delay time, and the interface formed due to layering fabrication. With the GO incorporated in the tensile region only (30% of the total depth), the flexural strength of the layered beam attained 90.91% of that of the beam, with GO uniformly distributed throughout the sample. Based on the results of rapid chloride migration tests, when 12 mm GO-incorporated cement mortar layer was used, the chloride migration coefficient was reduced by 21.45%. It was also found that the measured chloride migration coefficient of layered cement mortar agreed with the series model. The present investigation provides an efficient approach to use GO in cement-based materials from the perspective of mechanical and durability properties.

Section: Introductionmentioning

confidence: 99%

Efficient Use of Graphene Oxide in Layered Cement Mortar

Liu

Chen

et al. 2022

“…The velocity of ultrasonic pulses is influenced by the medium, and their propagation speeds in solids are higher than those in liquids and air. Therefore, the pulse velocity first increased and then decreased with increasing fly ash content [ 39 ]. In addition, the ultrasonic pulse velocity increased with an increase in curing age because the internal density of the specimen is higher in mortars with higher strengths; thus, the pulse velocity was higher.…”

Section: Resultsmentioning

confidence: 99%

Effect of Replacing Fine Aggregate with Fly Ash on the Performance of Mortar

Zhang

Yang

2023

Natural river sand resources are facing depletion, and large-scale mining pollutes the environment and harms humans. To utilize fly ash fully, this study used low-grade fly ash as a substitute for natural river sand in mortar. This has great potential to alleviate the shortage of natural river sand resources, reduce pollution, and improve the utilization of solid waste resources. Six types of green mortars were prepared by replacing different amounts of river sand (0, 20, 40, 60, 80, and 100%) with fly ash and other volumes. Their compressive strength, flexural strength, ultrasonic wave velocity, drying shrinkage, and high-temperature resistance were also investigated. Research has shown that fly ash can be used as a fine aggregate in the preparation of building mortar, thereby ensuring that green-building mortar has sufficient mechanical properties and better durability. The replacement rate for optimal strength and high-temperature performance was determined to be 80%.

“…It is, however, not entirely free of pores. Small amounts of sulphate eventually enter the sample and react to generate a small quantity of ettringite, which favours the specimens' strength [65].…”

Section: Acid Attackmentioning

confidence: 99%

Development of Mortars That Use Recycled Aggregates from a Sodium Silicate Process and the Influence of Graphene Oxide as a Nano-Addition

Ruiz Martinez,

Cifuentes,

Rios

et al. 2023

This research analyses how different cement mortars behave in terms of their physical and mechanical properties. Several components were necessary to make seven mixes of mortars, such as Portland cement, standard sand, and solid waste from a factory of sodium silicate, in addition to graphene oxide. Furthermore, graphene oxide (GO) was selected to reduce the micropores and increase the nanopores in the cement mortar. Hence, some tests were carried out to determine their density, humidity content, water absorption capacity, open void porosity, the alkali–silica reaction, as well as flexural and mechanical strength and acid resistance. Thus, standard-sand-manufactured mortars’ mechanical properties were proved to be slightly better than those manufactured with recycled waste; the mortars with this recycled aggregate presented problems of alkali–silica reaction. In addition, GO (in a ratio GO/cement = 0.0003) performed as a filler, improving the mechanical properties (30%), alkali–silica (80%), and acid resistance