Use of Plastic Waste in Bitumen

There has been a sudden increase in population and in the establishment of different industries due to which we are having waste pollution problems, including plastic waste. Discarding of plastic waste is a major problem, as it is non-biodegradable. When we mix plastic waste with bitumen, we are able to enhance bitumen's physical properties for a specific road mix. Then, bitumen's stability and water resisting capacity is upgraded. Plus, it acts as a more superior binding material than without the addition of plastic waste. Through this work, we are able to find the optimum percentage of bitumen to be substituted with plastic waste. This will also act as a part of smart waste disposal in smart cities and improve the air quality with increase environmental, economic parameters of the place leading to the improvement in human health in urban areas.

Preparation and Optimization of Mix ratio for C50T Girder Manufactured Sand and Concrete

Considering actual construction conditions of Binchuan-Heqing Highway, this paper provides the C50 mix ratio conforming to engineering requirements by strictly controlling the quality of raw materials, optimizing the design of mix ratio scientifically, preparing superior C50 concrete 0 with manufactured sand, and optimizing the concrete mix ratio based on the adjustment of fly ash replacement, water-cement ratio, polycarboxylate-type water reducer mixing amount, sand ratio, etc. The result indicates that, the water-cement ratio has a great influence on the concrete strength, and if the ratio of coal ash is high in the binding material, the early compressive strength of the concrete will increase slowly.

Fineness of Coal Fly Ash for Use in Cement and Concrete

Nowadays, coal is increasingly being used as an energy source in some countries. This coal-fired generation process, however, has the disadvantage that produces large quantities of coal fly ash. Its characteristics differ depending on the combustion conditions and the coal source. Fineness will influence early compressive strength in cement-based materials. The finer the binding material, the higher the early compressive strength. They can be used to produce high-volume fly ash (HVFA) concrete, self-compacting concrete (SCC), concrete for marine infrastructures, pervious concrete, roller compacted concrete (RCC) and so on.More than seven hundred samples of coal fly ash were collected from a coal-fired power plant for a period of ten years, and their fineness were characterized by sieving. The average fineness on 45 µm, 63 µm, 90 µm and 200 µm mesh sieves were 22.5%, 15.5%, 9.1% and 2.0%, respectively. Then, most of the coal fly ash particles were lower than 45 µm, i.e., from 15 to 30% were retained on the 45 µm sieve, and from 10 to 20% by mass of coal fly ash particles were retained on a 63 µm sieve. Fineness on a 45 µm sieve is a good indirect indicator of the residues on the 63 µm, 90 µm and 200 µm mesh sieves. Accordingly, it is suggested to broaden the range from ±5% to as high as ±7% regarding the fineness variation requirement. Finally, the tested coal fly ash can be applied as cement constituent.

Geopolymer Concrete: A Review

Geopolymer Concrete is a new innovative type of concrete, and it is used widely in the construction industries. This type of concrete comes into place due to reduced cement content usage in the construction of structures. Already we are using cement as a binding material widely in the construction sector, but the problem is due to the cement content Co2 emissions are mainly produced and one more problem is greenhouse gases are increasing rapidly during the manufacturing of cement. Then after a lot of researchers, finally we got a geopolymer as a replacement for cement. By replacing cement content with geopolymer, we can reduce the cost of construction and reuse the structural materials. So, this type of concrete is different from standard conventional concrete. We can minimize Co2 and greenhouse gases’ problem in the atmosphere and make the structure an environmentally friendly solution. So, this type of concrete is very famous in the construction industry, and there are benefits also excellent. So, it can be used widely in construction sectors worldwide. This paper may help understand Geopolymer Concrete for everyone quickly. It gives a quick review of the Geopolymer Concrete.

Geopolymer Concrete: A Review

Geopolymer Concrete is a new innovative type of concrete, and it is used widely in the construction industries. This type of concrete comes into place due to reduced cement content usage in the construction of structures. Already we are using cement as a binding material widely in the construction sector, but the problem is due to the cement content Co2 emissions are mainly produced and one more problem is greenhouse gases are increasing rapidly during the manufacturing of cement. Then after a lot of researchers, finally we got a geopolymer as a replacement for cement. By replacing cement content with geopolymer, we can reduce the cost of construction and reuse the structural materials. So, this type of concrete is different from standard conventional concrete. We can minimize Co2 and greenhouse gases’ problem in the atmosphere and make the structure an environmentally friendly solution. So, this type of concrete is very famous in the construction industry, and there are benefits also excellent. So, it can be used widely in construction sectors worldwide. This paper may help understand Geopolymer Concrete for everyone quickly. It gives a quick review of the Geopolymer Concrete.

The Influence of Phosphogypsum Microstructure on the Main Properties of Press-Formed Samples

The storage of the phosphogypsum in stockpiles causes serious environmental problems. In order to avoid them, this by-product should be utilised. Hence, one solution is to employ it as a binding material, so that its structural and binding properties must be satisfactory. Depending on the type of original phosphate rock, the microstructure of phosphogypsum may differ, determining its main physical-mechanical properties. However, research with comparative analyses of the properties of phosphogypsum from different origins is almost inexistent. Therefore, in this study, the microstructure of phosphogypsum from two different sources is analysed: the first type is from Kovdor mine (Russia); the second is a mixture between material from Kirov (Russia) and Casablanca (Morocco) mines. The microstructure of both phosphogypsum types was analysed and compared by applying SEM-DES analysis and by measuring the loss on ignition. In order to obtain high mechanical properties, the material was processed by press-forming. Eventually, the mechanical properties of hardened phosphogypsum of both types were obtained by compression test and then compared.

Mechanical strength variation of zeolite-fly ash geopolymer mortars with different activator concentrations

Zeolite is of a significance for geopolymers as it is a natural precursor and does not require additional heat treatment for activation. However, aluminosilicates sourced from natural sources require additional handling for the best use of exploitation. In this study, geopolymers were synthesized by binary use of zeolite and fly ash as main binding material and sodium silicate and sodium hydroxide as alkaline activator. The influence of alkaline activator ratios and sodium hydroxide concentrations on the compressive strength and flexural strength of the zeolite-fly ash based geopolymers were studied. In this research, zeolite-fly ash based geopolymer mortars were produced by using 50% of natural zeolite (clinoptilolite) and 50% of C-type fly ash. Four different activator ratios (Na2SiO3/NaOH: 1, 1.5, 2 and 2.5) and two sodium hydroxide molarities (10M and 12M) was utilized to activate zeolite and fly ash in order to determine the effect of these parameters on the mechanical strengths of the produced geopolymer mortars. The results indicated that as the alkaline activator ratio and NH molarity were increased the compressive strength of the zeolite-fly ash based geopolymers also increased. The maximum compressive and flexural strength values obtained after 28 days of curing were 20.1 MPa and 5.3 MPa respectively and corresponds when used activator ratio of 2.5 and sodium hydroxide concentration of 12 molarity. The obtained results indicated that both the alkaline activator ratio and sodium hydroxide concentration affected the compressive and flexural strengths of zeolite-fly ash based geopolymer mortar specimens.