Ahmadi et al 2021a - Revision history

Rimni: /* 3.3. Investigation the effect of the water content and carboxylate percentage on the concrete compression strength */

2022-02-01T12:39:26Z

‎3.3. Investigation the effect of the water content and carboxylate percentage on the concrete compression strength

Rimni at 12:50, 31 January 2022

2022-01-31T12:50:53Z

Rimni at 12:49, 31 January 2022

2022-01-31T12:49:50Z

Rimni at 10:47, 28 January 2022

2022-01-28T10:47:41Z

Rimni at 10:46, 28 January 2022

2022-01-28T10:46:10Z

Rimni: /* 3.2 Investigation the effect of the water content and carboxylate percentage on the concrete slump */

2022-01-28T10:40:55Z

‎3.2 Investigation the effect of the water content and carboxylate percentage on the concrete slump

Rimni at 10:39, 28 January 2022

2022-01-28T10:39:26Z

Rimni at 10:38, 28 January 2022

2022-01-28T10:38:22Z

Rimni: /* 2. Materials and methods */

2022-01-28T10:36:49Z

‎2. Materials and methods

Rimni: /* 3.4. Economical investigation of the prepared concretes */

2022-01-28T10:29:43Z

‎3.4. Economical investigation of the prepared concretes

@@ Line 496: / Line 496: @@
 ''Slump of the concrete produced with grade 400 Kg/m<math>^3</math>:'' The changes in compressive strength against water to cement ratio in concrete samples with a grade of 400 kg/m<math>^3</math> and polycarboxylate superplasticizer is shown in [[#tab-4|Table 4]], [[#img-8|Figure 8]], and [[#img-9|Figure 9]] (b).  According to the results, with increasing the ratio of water to cement, the amount of compressive strength has decreased. Also, with the increase of water to cement ratio from 0.39 to 0.45, the final 28-day resistance value has reached from 48 MPa to 32 MPa, which was a decrease equal to 33%.
-''Slump of the concrete produced with grade 450 Kg/m<math>^3</math>:'' Based on the results, changes in compressive strength in concrete samples with a grade of 450 kg/m<math>^3</math> and polycarboxylate superplasticizer with increasing water to cement ratio has a decreasing trend ([[#tab-4|Table 4]], [[#img-8|Figure 8]], and [[#img-9|Figure 9]] (c). By increasing the water to cement ratio from 0.34 to 0.39, the final strength of 28 days has increased from 51 MPa to 38 MPa, which was a decrease of 25%.
+''Slump of the concrete produced with grade 450 Kg/m<math>^3</math>:'' Based on the results, changes in compressive strength in concrete samples with a grade of 450 kg/m<math>^3</math> and polycarboxylate superplasticizer with increasing water to cement ratio has a decreasing trend ([[#tab-4|Table 4]], [[#img-8|Figure 8]], and [[#img-9|Figure 9]] (c)). By increasing the water to cement ratio from 0.34 to 0.39, the final strength of 28 days has increased from 51 MPa to 38 MPa, which was a decrease of 25%.
 ''Slump of the concrete produced with grade 500 Kg/m<math>^3</math>:'' Based on the results presented in [[#tab-4|Table 4]], [[#img-8|Figure 8]] and [[#img-9|Figure 9]] (d), the changes in compressive strength in concrete samples with a grade of 500 kg/m<math>^3</math> and having polycarboxylate superplasticizer with increasing water to cement ratio was decreased. Also, by increasing in water to cement ratio from 0.3 to 0.35, the final 28-day resistance value for these samples has increased from 55 MPa to 43 MPa. Numerically, this decreasing trend was equal to 22%.

@@ Line 440: / Line 440: @@
 |  51
 |-style="text-align:center"
-|  rowspan='6' |500(Kg/m<math>^3</math>)
+|  rowspan='6' |500 (Kg/m<math>^3</math>)
 |  M13
 |  0.3

@@ Line 280: / Line 280: @@
 |  147
 |-style="text-align:center"
-|  rowspan='6' |500(Kg/m<math>^3</math>)
+|  rowspan='6' |500 (Kg/m<math>^3</math>)
 |  M13
 |  0.3

@@ Line 337: / Line 337: @@
 ''Slump of the concrete produced with grade 450 Kg/m<math>^3</math>:'' The changes of slump number against water to cement ratio for samples (M7-M12) with a grade of 450 kg/m<math>^3</math> are shown in [[#img-6|Figure 6]], and [[#tab-3|Table 3]]. Based on the results, with increasing water to cement ratio, the slump number decreased. Thus, by reducing the water to cement ratio from 0.39 to 0.34, the amount of slump has increased from 31 mm to 147 mm, which was a growth equal to 4.7 times. Moreover, for concrete samples with a grade of 450 kg/m<math>^3</math>, it has been observed that with increasing the percentage of polycarboxylate superplasticizer, the amount of slump of samples increased. According to the qualitative identifications, with increasing the percentage of superplasticizer from 0.3% to 1.6%, the slump number increased from 31 mm to 147 mm, which can be said that the ratio of slump growth to the percentage of superplasticizer was equal to 0.88(mm/% superplasticizer).
-''Slump of the concrete produced with grade 500 Kg/m<math>^3</math>:'' Slump changes against water to cement ratio for concrete samples with a grade of 500 kg/m<math>^3</math> are shown in [[#img-6|Figure 6]], and [[#tab-3|Table 3]]. The results showed that with decreasing water to cement ratio, the slump number had an increasing trend. Thus, by reducing the ratio of water to cement from 0.35 to 0.30, the amount of slump has increased from 25 mm to 123 mm, which was a growth equal to 4.9 times. Finally, changes in the slump number against the percentage of polycarboxylate superplasticizer for samples with a grade of 500 kg/m<math>^3</math> are shown in [[#img-7|Figure 7]] and [[#tab-3|Table 3]]. It has been observed that with increasing the percentage of polycarboxylate superplasticizer, the slump number of samples has increased. This means that, with increasing the percentage of superplasticizer from 0.3% to 1.6%, the slump number has increased from 25 mm to 123 mm, which can be said that the ratio of slump growth to the percentage of superplasticizer growth was equal to 0.92(mm/% superplasticizer).
+''Slump of the concrete produced with grade 500 Kg/m<math>^3</math>:'' Slump changes against water to cement ratio for concrete samples with a grade of 500 kg/m<math>^3</math> are shown in [[#img-6|Figure 6]], and [[#tab-3|Table 3]]. The results showed that with decreasing water to cement ratio, the slump number had an increasing trend. Thus, by reducing the ratio of water to cement from 0.35 to 0.30, the amount of slump has increased from 25 mm to 123 mm, which was a growth equal to 4.9 times. Finally, changes in the slump number against the percentage of polycarboxylate superplasticizer for samples with a grade of 500 kg/m<math>^3</math> are shown in [[#img-7|Figure 7]] and [[#tab-3|Table 3]]. It has been observed that with increasing the percentage of polycarboxylate superplasticizer, the slump number of samples has increased. This means that, with increasing the percentage of superplasticizer from 0.3% to 1.6%, the slump number has increased from 25 mm to 123 mm, which can be said that the ratio of slump growth to the percentage of superplasticizer growth was equal to 0.92 (mm/% superplasticizer).
 Many studies tried to enhance the slump in concrete by introducing new superplasticizers. Shenoy et al. produced new organic superplasticizer from Albizia Saman pod which decreased water content in 10% in same slump [25]. By using such superplasticizer the compressive strength increased in 6%. Also, mineral admixtures such as silica fume (10%) caused 30% decrease in slump flow [26].  Based on the results represented for comparing the changes of slump against the ratio of water to cement in concretes with different grades of cement with polycarboxylate superplasticizer, it has been observed that with increasing the ratio of water to cement, the slump number has decreased in the all three grades. Also, by increasing the grade of cement in concrete in the fixed ratio of water to cement, concrete with lower cement grade (G400) had more slump number than others. It has been observed that with increasing the percentage of polycarboxylate superplasticizer, the slump number generally had an upward trend. Also, by increasing the grade of cement in concrete in the percentage of fixed polycarboxylate superplasticizer, concrete with higher grade had less slump number.

@@ Line 167: / Line 167: @@
 {| style="text-align: center; border: 1px solid #BBB; margin: 1em auto; width: auto;max-width: auto;"
 |-
-|style="padding:10px;"| [[Image:Review_649842671165-image5.png|366px]]
+|style="padding:10px;"| [[Image:Review_649842671165-image5.png|400px]]
 |- style="text-align: center; font-size: 75%;"
 | colspan="1" style="padding:10px;"| '''Figure 3'''. Slump test for produced concretes in laboratory environment

@@ Line 209: / Line 209: @@
 ===3.2 Investigation the effect of the water content and carboxylate percentage on the concrete slump===
-In this paper, for the means of true investment, the slump results of three selected grades of concretes types 400, 450, and 500 (Kg/m<math>^3</math>), respectively was presented in two parameter type: water per cement content and polycarboxylate per cement content. Experimental design was according to multi factor at a time analysis. For the purpose, each of two factors including water and polycarboxylate content was arranged in 6 levels for three cement grades ([[#tab-3|Table 3]]). Gui-zhong et al. illustrated that the water content affecting the slump flow by 15(cm/80% of water) [24]. According to the Gui-zhong et al.  outcomes the slump was related to the salinity, and by increasing the salinity the slump decreased.
+In this paper, for the means of true investment, the slump results of three selected grades of concretes types 400, 450, and 500 (Kg/m<math>^3</math>), respectively was presented in two parameter type: water per cement content and polycarboxylate per cement content. Experimental design was according to multi factor at a time analysis. For the purpose, each of two factors including water and polycarboxylate content was arranged in 6 levels for three cement grades ([[#tab-3|Table 3]]). Gui-zhong et al. illustrated that the water content affecting the slump flow by 15 (cm/80% of water) [24]. According to the Gui-zhong et al.  outcomes the slump was related to the salinity, and by increasing the salinity the slump decreased.
 <div class="center" style="font-size: 75%;">'''Table 3'''. Multi factor experiment designed for two factors (water content and carboxylate content) in three cement grades</div>

@@ Line 133: / Line 133: @@
 {| class="wikitable" style="margin: 1em auto 0.1em auto;border-collapse: collapse;font-size:85%;width:auto;"
 |-style="text-align:center"
-! Parameter !! Value
+! style="text-align:left" | Parameter !! Value
 |-style="text-align:center"
-|  Mold Size
+|  style="text-align:left" |Mold Size
 |  941.2 cm<math>^3</math>
 |-style="text-align:center"
-|  Mold Diameter
+|  style="text-align:left" |Mold Diameter
 |  10.2 cm
 |-style="text-align:center"
-|  Mold height
+|  style="text-align:left" |Mold height
 |  11.5 cm
 |-style="text-align:center"
-|  Hammer weight
+|  style="text-align:left" |Hammer weight
 |  4500 g
 |-style="text-align:center"
-|  Number of layers
+|  style="text-align:left" |Number of layers
 |  5
 |-style="text-align:center"
-|  Falling height
+|  style="text-align:left" |Falling height
 |  45 cm
 |-style="text-align:center"
-|  Number of strokes per layer
+|  style="text-align:left" |Number of strokes per layer
 | 25
 |-style="text-align:center"
-|  The resulting compaction energy per unit volume
+|  style="text-align:left" |The resulting compaction energy per unit volume
 |  905.2 g/cm<math>^3</math>
 |}

@@ Line 17: / Line 17: @@
 ==2. Materials and methods==
-Ordinary Portland cement (OPC) was manufactured by a local cement company (ABYEK). The clay was calcined at 800 °C in a semi-industrial rotary kiln with a residence time of 15 minutes. Rietveld analysis of calcined clay showed that it contained 42% calcined kaolinite (metakaolin) and the remaining kaolinite, quartz (16%) without calcium and illite, anatase and hematite (total <math> <2\%</math> ). The chemical composition (from X-ray fluorescence analysis) and the properties of fly ash and iron slag are listed in [[#tab-1|Table 1]].
+Ordinary Portland cement (OPC) was manufactured by a local cement company (ABYEK). The clay was calcined at 800 °C in a semi-industrial rotary kiln with a residence time of 15 minutes. Rietveld analysis of calcined clay showed that it contained 42% calcined kaolinite (metakaolin) and the remaining kaolinite, quartz (16%) without calcium and illite, anatase and hematite (total <math> <2\%</math>). The chemical composition (from X-ray fluorescence analysis) and the properties of fly ash and iron slag are listed in [[#tab-1|Table 1]].
 <div class="center" style="font-size: 75%;">'''Table 1'''. Results of elemental analysis of slag and fly ash samples obtained from XRF analysis</div>

← Older revision		Revision as of 10:29, 28 January 2022
Line 602:		Line 602:


−	For a detailed understanding of the step-by-step impact of carboxylates on the samples price, the production costs is classified in three classes; 6-8$, 8-10$, and 10-12$ ([[#img-11\|Figure 11]]. As it illustrated in [[#img-10\|Figure 10]], all G-400, and G-450 samples was classified in 6-8$, and 8-10$. Samples with cement grade of 400 except M6 were low than 8$, and the samples with cement grade of 500 were low than 10$ except M18. In according with these results, M18 had lower economic justification among the samples.	+	For a detailed understanding of the step-by-step impact of carboxylates on the samples price, the production costs is classified in three classes; 6-8$, 8-10$, and 10-12$ ([[#img-11\|Figure 11]]). As it illustrated in [[#img-10\|Figure 10]], all G-400, and G-450 samples was classified in 6-8$, and 8-10$. Samples with cement grade of 400 except M6 were low than 8$, and the samples with cement grade of 500 were low than 10$ except M18. In according with these results, M18 had lower economic justification among the samples.

	<div id='img-11'></div>		<div id='img-11'></div>