Today, in order to strengthen the mechanical properties and to reduce cement consumption, reduce costs, reduce energy consumption and reduce environmental pollutants, various industrial pozzolans such as microsilica and various materials have been used in concrete construction. However, the application of additives such as polypropylene fibers and fly ash, which have many resources in Iran, has received less attention from concrete technology experts. To do this, 24 samples were prepared for different ratios of polypropylene fibers and ash. In the experiments, 12 samples were selected for compressive strength and 12 samples for tensile strength at the ages of 7, 28 and 42 days. The results of the experiments showed that in general, polypropylene fibers and fly ash have improved the compressive strength and tensile strength of ordinary concrete. Also, based on the results of the research, it can be concluded that in terms of mechanical properties, the performance of concrete made of polypropylene fibers is much better than concrete containing fly ash. Also, the results of the laboratory study were numerically evaluated in SAP software and in a 10-story structure with three types of ordinary concrete, concrete with fly ash and concrete with polypropylene fibers with the values obtained from the laboratory results of compressive strength and Tensile strength was evaluated and the results showed that polypropylene fibers have a good performance in numerical and laboratory tests compared to ordinary concrete and concrete with fly ash.
In this chapter, in the first part, the results obtained from the study of mechanical properties and durability, including tests of compressive strength, indirect tensile strength, flexural strength, modulus of elasticity, electrical resistance, RCPT and RCMT are described. In the second part, a summary of the diagrams and tables obtained from the study of failure mechanical properties, the two methods of failure work and the size effect are mentioned. At the end of the chapter, suggestions are provided to continue the research in the reviewed cases
Mixing plan is considered to study the mechanical properties of both. The first series with 9 designs to obtain the control concrete mixing design with the highest compressive strength and the second series mixing design with 10 designs to investigate the effect of single steel fibers. Replace and add
0.25% by volume of polypropylene fabric was selected on the mechanical properties of high-strength geopolymer concrete
1- In the mixing plan of the first series, it was observed with increasing the molarity of the solution from 8 to 16 and increasing the ratio of sodium silicate to
Sodium hydroxide increases the compressive strength from 9 to 3 due to the rapid dissolution of alumina silicate and alkalinity and the formation of a large amount of alumina silicate polymer gel. 2- In the second series mixing plan, by increasing the percentage of fibers, all the mechanical properties of super-capable geopolymer concrete, including
Compressive strength, tensile strength, flexural strength, modulus of elasticity increase dramatically. This increase is due to reinforcement
It is the contact area and at all ages the 2% steel weave design achieved only the highest characteristics. 3- Replacing polypropylene fibers due to its low tensile strength compared to steel fibers reduces the strength
On the other hand, the addition of polypropylene fibers causes the synergistic effect of steel and polypropylene fibers, bridging on micro-cracks and their large number, shows the positive effect of polypropylene fibers, which is due to the positive effect. Low tensile strength of polypropylene fibers is small. In general, combining fibers in terms of dimensions, material and type of fibers will not be positive or their effect will be negative.
The second series mixing design with 10 designs was selected in order to influence the replacement and addition of polypropylene fibers to steel fiber designs on the durability properties of high-strength geopolymer concrete.
4- In two methods of electrical resistance and RCPT, the addition of weaving has reduced the flow in Yemen due to the limitation of cracks caused by drying and plastic shrinkage, and also the addition of polypropylene fibers due to conductivity.
Very little has caused a lower flow rate than only steel fiber samples. On the other hand, the amount of flow changes in the method
RCPT is higher than electrical resistance due to the increase in temperature which in turn increases the current
Due to the influence of other ions such as OH and the conductivity of steel fibers on the passage current in the previous two methods, the durability properties of RCMT method, which shows the direct effect of chlorine ion, have been investigated and the results of chlorine ion resistance in this method are better. And it is more acceptable and in the excellent range. In this method, as in previous methods, the addition of fibers has improved durability and polypropylene fibers have a positive effect on hybrid designs | Is
Due to the positive effect of polypropylene fibers in the second series of the mixing design, the mixing design of the third series with seven designs was selected to investigate the fracture characteristics of super-capable geopolymer fiber by two methods of failure work and size effect.
06 Adding fibers increases the area below the graph and thus increases the GF failure energy. In designs containing steel fibers, only the growth rate is higher than in hybrids, and also in designs containing 2% of steel fibers.
Only the highest amount of growth was observed and the replacement of polypropylene fibers reduced the rate of increase of shake energy
Be, 7- According to Figure (47), it was observed that the replacement of polypropylene fibers has a great impact on the displacement load diagram.
Does not and steel fiber designs overlap with each other only with its hybrid design with the same amount of fiber yield |
They have a good relationship between the refractive energy and the volume percentage of single and hybrid steel fibers with the value of R2 in 1989 and / 978, respectively. Relationship
Is linear - with the addition of fibers the amount of characteristic length and thus its ductility increases and in the design of 2% steel fibers
Only the highest growth rate was observed, also the replacement of polypropylene fibers reduces the characteristic length. 10- The relationship between characteristic length and volume percentage of single and hybrid steel fibers with R2 value, respectively
0.92 and 878 / • are linear relationships
11- With the addition of fibers, the amount of fracture energy increases in the size effect method and also the maximum amount of growth in the design
Contains only 2% of the observed steel fibers. Also replacing polypropylene fabric reduces the amount
Energy failed. | 12. Relation of fracture energy and volume percentage of single and hybrid steel fibers with * R value respectively
0/906 and 1899 relational | It is linear 13. With the addition of weaving, the effective length increases and as a result, the brittleness of the concrete decreases. Design of two percent of the most steel fibers
Showed the amount of growth. Replacing polypropylene fibers also reduces effective length. 14- The relationship between effective length and volume percentage of single and hybrid steel fibers with quantity R respectively 0.907 and 0.9 linear relation
15. The amount of Kwc fracture toughness increases with the addition of fibers. The 2% design of steel fibers showed the highest amount of toughness. Adding polypropylene fibers also reduces fracture toughness. | 16. Relationship between fracture toughness and volume percentage of single and hybrid steel fibers with R2 value, respectively
Investigation of concrete fibers mechanical properties of super-strong geopolymer concrete based on slag and fly ash Investigation of fracture parameters of high-strength geopolymer concrete containing glass and carbon fibers Survey of high-strength parameters Geopolymer based on slag and fly ash
Investigating the dimensions of reinforcement laminates made of super-capable geopolymer fiber reinforced concrete on one-sided slab reinforcement 6- Comparing the effect of reinforcing laminates made of super-reinforced geopolymer fiber reinforced concrete in compressive, tensile and
The sides on one-sided slab reinforcement
