In order to determine the architectural utility and mechanical properties of reed fiber, coconut fiber and steel fiber concrete, we need to test the slump, tensile strength and flexural strength of specimens raised for 7 days and 28 days to obtain relevant data and analyze its relevant mechanical properties and the scope of architectural use. The test specimens are shown in Fig. 4a and 4b, and the mechanical properties are shown in Fig. 5a and 5b, and the test results are shown in Tables 5 and 6. In order to determine the architectural utility and mechanical properties of reed fiber, coconut fiber and steel fiber concrete, we need to test the slump, tensile strength and flexural strength of specimens raised for 7 days and 28 days to obtain relevant data and analyze its relevant mechanical properties and the scope of architectural use. The fabrication of the specimen is shown in Fig 6a and 6b, the flexural tests are shown in Fig 7a and 7b, and the compressive tests are shown in Fig 8a and 8b, and the test results are shown in Tables 5 and 6.The slump measurements of reed fiber, coconut fiber and steel fiber are shown in Table 7.
Table-5, normal stress (σu) 0 MPa at reed fiber, coconut fiber, steel fiber 7, 28 days flexural strength Mpa.
Number
|
Substitution parameters
|
Plain concrete
|
Reed fiber
|
Coconut fiber
|
Steel Fiber
|
σu/ MPa
|
r/%
|
7d
|
28d
|
7d
|
28d
|
7d
|
28d
|
7d
|
28d
|
C1
|
0
|
0.5%
|
3.6
|
4.1
|
4.1
|
5.0
|
3.9
|
4.9
|
4.1
|
4.9
|
C2
|
0
|
1%
|
3.5
|
3.9
|
4.0
|
4.9
|
4.1
|
4.8
|
4.2
|
5.1
|
C3
|
0
|
1.5%
|
3.9
|
4.5
|
4.3
|
5.8
|
4.0
|
5.7
|
4.6
|
6.0
|
C4
|
0
|
2%
|
4.1
|
4.2
|
4.8
|
5.9
|
4.5
|
5.9
|
4.8
|
5.8
|
C5
|
0
|
2.5%
|
4.0
|
4.2
|
4.5
|
5.4
|
4.2
|
5.3
|
4.6
|
5.3
|
C6
|
0
|
3%
|
3.8
|
4.0
|
4.4
|
4.9
|
4.4
|
4.7
|
4.5
|
4.8
|
Table-6, normal stress (σu) 0MPa at reed fiber, coconut fiber, steel fiber 7, 28 days compressive strength Mpa.
Number
|
Substitution parameters
|
Plain concrete
|
Reed fiber
|
Coconut fiber
|
Steel Fiber
|
σu/ MPa
|
r/%
|
7
|
28d
|
7d
|
28d
|
7d
|
28d
|
7d
|
28d
|
C1
|
0
|
0.5%
|
35.8
|
44.1
|
35.2
|
44.1
|
33.2
|
43.5
|
34.8
|
53.6
|
C2
|
0
|
1%
|
35.1
|
42.3
|
37.6
|
45.6
|
35.1
|
46.7
|
36.6
|
52.1
|
C3
|
0
|
1.5%
|
36.3
|
42.8
|
40.1
|
43.8
|
39.6
|
47.3
|
46.3
|
54.5
|
C4
|
0
|
2%
|
38.6
|
41.5
|
43.8
|
50.7
|
43.2
|
49.2
|
44.5
|
52.8
|
C5
|
0
|
2.5%
|
39.0
|
40.2
|
41.5
|
48.3
|
42.1
|
46.5
|
45.2
|
50.1
|
C6
|
0
|
3%
|
38.3
|
42.5
|
40.6
|
43.9
|
42.7
|
43.1
|
45.6
|
51.2
|
Table-7, reed fiber, coconut shell fiber, steel fiber slump measurement
Serial number
Slump (mm)
|
Plain concrete
|
Reed fiber
|
Coconut fiber
|
Steel Fiber
|
C1
|
195
|
190
|
196
|
190
|
C2
|
180
|
200
|
204
|
185
|
C3
|
185
|
205
|
198
|
200
|
C4
|
198
|
205
|
203
|
198
|
C5
|
200
|
195
|
210
|
200
|
C6
|
205
|
210
|
216
|
210
|
In order to explore the different functions of using reed fiber concrete, steel fiber concrete, coconut fiber concrete and ordinary concrete in green building materials as well as the different mechanical properties (tensile and flexural), we used python software analysis to do the relevant graphical analysis of the above test data. The programming is as follows: the test analysis results are detailed in Figs. 8, 9, 10, 11 and 12.
import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif'] = ['SimHei']
plt.rcParams['axes.unicode_minus'] = False
df = pd.read_excel(r "C:\Drivers\onedrive\desk\1.xlsx")
x = df.iloc[:,0]
y1 = df.iloc[:,1]
y2 = df.iloc[:,2]
y3 = df.iloc[:,3]
y4 = df.iloc[:,4]
plt.figure(figuresize = (10,5),dpi = 100)
plt.xlabel('Replace parameter amount r/%')
plt.ylabel('7-day flexural strength of concrete (MPa)')
plt.plot(x,y1,marker= 'o',label="Ordinary Concrete")
plt.plot(x,y2,marker= '>',label="Reed Fiber Concrete")
plt.plot(x,y3,marker= 's',label="Coconut Fiber Concrete")
plt.plot(x,y4,marker= 'p',label="Steel Fiber Reinforced Roncrete")
Analyzing Fig. 8, we clearly observe that the 7-day flexural strength of the fiber concrete has a significant increase compared to the normal concrete, with the steel fiber showing the most significant increase, followed by the reed fiber and finally the coconut fiber. the peak point of the 7-day flexural strength lies at 2% of the fiber added. The flexural strength increases with the amount of fiber added, and after reaching the peak of 2%, the flexural stress decreases as the amount of fiber increases.
Analyzing Fig. 9, we clearly observe that the 28-day flexural strength of fiber concrete is significantly higher than that of ordinary concrete, with the peak point of steel fiber at 1.5%, followed by a gradual decrease in flexural strength as the amount of fiber ; the peak points of reed fiber and coconut shell fiber also maintain the same position with the 7-day flexural strength value, still maintaining a 2% fiber addition gradient. The commonality of the three fibers is that they can all enhance the flexural strength of concrete, which is normally distributed in a certain amount of fiber addition to continuously increase the flexural strength, and after reaching the highest stress peak, the flexural strength will instead gradient down with the increase in the amount of fiber. The relationship of flexural stress of fiber concrete is: steel fiber concrete > reed fiber concrete > coconut fiber concrete.
Analyzing Fig. 10, we clearly observe a significant increase in the 7-day compressive strength of fiber concrete compared to normal concrete, with positive correlation curves for reed fiber concrete and coconut fiber concrete. The commonality lies in the fact that the compressive strength of the specimens of fiber concrete increases along with the gradient of fiber admixture. After reaching the peak of 2%, the increase in fiber does not enhance the compressive strength of the fiber concrete specimens, but instead leads to a subsequent decrease in the compressive strength of the specimens as the fiber admixture increases. In contrast, the strength of the fiber concrete specimens was enhanced significantly in the 0.5%-1.5% fiber admixture interval, followed by a decreasing trend in compressive strength.
Analyzing Fig. 11, we clearly observe that the 28-day compressive strength of fiber concrete is significantly higher than that of ordinary concrete, and the compressive strength of steel fiber concrete is highest at 1.5% fiber admixture, and gradually decreases with the increasing fiber admixture. The compressive strength of coconut shell fiber and reed fiber showed a linear correlation, both of which were accompanied by an increase in the amount of gradient fiber and the compressive strength of concrete specimens gradually increased, and after reaching a peak of 2%, the compressive strength gradually decreased with the increase of fiber.
Analyzing Fig 12, we clearly observe that the 28-day compressive strength of fiber concrete is significantly higher than that of ordinary concrete, and the compressive strength of steel fiber concrete is highest at 1.5% fiber admixture, and gradually decreases with the increasing fiber admixture. The compressive strength of coconut shell fiber and reed fiber showed a linear correlation, both of which were accompanied by an increase in the amount of gradient fiber and the compressive strength of concrete specimens gradually increased, and after reaching a peak of 2%, the compressive strength gradually decreased with the increase of fiber.
From the analysis of Fig 13 above, it can be seen that the measured concrete slump is within the experimental design slump range (180mm-220mm), and the slumps of the three fiber concrete are generally smaller than those of the normal concrete fibers, with the reed fiber having the smallest slump, followed by the coconut shell fiber and finally the steel fiber. Their slump all decreases with the increasing amount of fiber gradient, thus illustrating the tendency of adding fibers to concrete to produce flexural aggregation reaction. In particular, this flexural aggregation of plant fibers reduces the fluidity of pumped concrete.
The effect on the strength of concrete by varying the normal stress and varying the amount of fiber gradient while the water-cement ratio, additives, coarse aggregates and material dosage are kept constant. The scatter plot graph was analyzed using python software and the scatter plot was fitted using five polynomials, in which the sample coefficients of six fits basically tended to 1. Therefore, this test was again confirmed to be error-free. The analysis can be obtained that the flexural and compressive strength of concrete is maximum when the content of non-metallic plant fibers (coconut shell fiber and reed fiber) is 2%. The flexural and compressive strength of concrete is maximum when the content of steel fiber is 1.5%.
The flexural curve fitting equation
(y7 = (7.467*10**9)*x**5 - (6.133*10**8)*x**4+ (1.827*10**7)*x**3- (2.407*10**5)*x**2 + 1399*x + 1.2
y8 = (-4.267*10**9)*x**5 + (4.533*10**8)*x**4- (1.813*10**7)*x**3+ (3.287*10**5)*x**2- 2544*x + 11.5
y9 = (1.333*10**10)*x**5 - (1.153*10**9)*x**4+ (3.72*10**7)*x**3- (5.512*10**5)*x**2 + 3702*x -4.8
y10 = (-1.867*10**9)*x**5 + (2.467*10**8)*x**4- (1.157*10**7)*x**3+ (2.338*10**5)*x**2- 1930*x + 10
y11 = (1.067*10**9)*x**5 - (6*10**7)*x**4+ (6*10**5)*x**3+ (1.35*10**4)*x**2–195.7*x + 4.7
y12 = (-8.267*10**9)*x**5 + (7.933*10**8)*x**4- (2.863*10**7)*x**3+ (4.702*10**5)*x**2- 3329*x + 12.9)
The fitting equation for the compressive curve
(y7=(6.107*10**10)*x**5 - (5.133*10**9)*x**4+ (1.589*10**8)*x**3- (2.244*10**6)*x**2+ (1.477*10**4)*x + 0.6
y8 = (1.475*10**11)*x**5 - (1.306*10**10)*x**4+ (4.294*10**8)*x**3- (6.443*10**6)*x**2+ (4.344*10**4)*x -58
y9 = (2.8*10**10)*x**5 - (2.12*10**9)*x**4+ (5.583*10**7)*x**3- (6.13*10**5)*x**2 + 3237*x + 26.6
y10 = (5.227*10**10)*x**5 - (4.573*10**9)*x**4+ (1.489*10**8)*x**3- (2.25*10**6)*x**2+ (1.588*10**4)*x + 4.4
y11=(-1.339*10**11)*x**5+(1.227*10**10)*x**4-(4.217*10**8)*x**3+ (6.647*10**6)*x**2 - (4.596*10**4)*x + 143.9
y12 = (-2.507*10**10)*x**5 + (2.62*10**9)*x**4- (1.009*10**8)*x**3+ (1.75*10**6)*x**2- (1.332*10**4)*x + 87.5)
From the above analysis of the tables in Fig 14-17, it can be concluded that all three fibers can increase the mechanical and mechanical properties of concrete at normal stress σu = 0 MPa and are correlated. The best admixture ratio of reed fiber concrete and coconut fiber concrete is 2%, which can effectively enhance the mechanical properties of concrete both in 7-day flexural and compressive; and 28-day flexural and compressive. The optimum admixture ratio of steel fiber is 1.5%, and the steel fiber is much higher than the plant fiber in increasing the flexural and flexural properties of concrete. This finding (optimum admixture ratio of plant fibers) is in general agreement with the results found by Yashwanth M Ka, Sushmitha G S, in Evaluation of Compressive Strength of Coir Fibre Reinforced Concrete [25]. It shows that our scientific test data are rigorous and play a crucial role in the research work of this paper, and it provides new directions for scientific researchers in the Republic of Belarus on new green building materials.