**4. Self-compacting concrete (SCC)**

Self-compacting concrete (SCC) has received wide attention and used in the construction industry worldwide since its development [59]. SCC is featured with high fluidity, and at the same time, high resistance to segregation and is placed purely under its weight without the need for vibration [60–62]. SCC properties are the result of modifying the composition of CVC by incorporating high powder content that has been mainly cement. However, the use of high cement content is not desirable as it will increase the cost and has other negative environmental effects. Replacing cement in SCC mixtures with waste powder is a trend gaining a great deal of attention with the growing awareness toward environmental protection and sustainable construction [63–70]. CWP is used to partially replace cement to produce eco-friendly SCC. The cement content in the control mixture is 500 kg/m3 based on the preliminary mix design. The powder content of the control mixture meets the recommended value by EFNARC specifications [71]. The cement is partially replaced by the CWP in 20, 40 and 60% by weight. The concrete mixture is expected to yield compressive strength in the range of 80 MPa. The details of the mixtures' proportions are given in **Table 6**.

Ordinary Portland cement (OPC) is used as the main binder. The specific surface area of cement is 380 m<sup>2</sup> /kg. Natural crushed stone of maximum size 9.5 mm is used as coarse aggregate. The specific gravity is 2.65 while the absorption was 0.7%. Natural sand with fineness modulus between 2.5 and 2.7 is used as fine aggregate. The specific gravity is 2.63.

Several tests are conducted to investigate the effect of replacing cement with CWP on the fresh properties of the produced concrete. Unconfined flowability of the produced SCC mixture is assessed by the slump flow test in accordance to ASTM C1611 [72]. Passing ability is evaluated through two tests namely the J-ring (i.e., ASTM C1621 [73]), and L-box. The segregation resistance is measured through conducting the GTM segregation column test conforming to ASTM C1610 [74]. Finally, the viscosity is measured by following the V-funnel test procedure described in the EFNARC specification [71]. On the other hand, compressive strength is performed at two test ages (i.e., 7 and 28 days) in order to evaluate the strength development. The durability characteristic is evaluated by conducting the bulk electrical resistivity as per ASTM C1760 [53] at 28 and 90 days of age. Triplicate samples are used to


**23**

**Figure 17.** *Slump flow results.*

**Figure 16.**

*Different tests conducted on SCC.*

*The Use of Ceramic Waste Powder (CWP) in Making Eco-Friendly Concretes*

conduct the compressive strength and the bulk electrical resistivity tests and the average results are used. **Figure 16** shows the different tests conducted. The microstructure development is judged by measuring the permeable pore volume at 28 and 90 days of age. Also, the pore system (i.e., total porosity and median pore diameter) is assessed using mercury intrusion porosimetry (MIP). The MIP is conducted at

Slump flow test evaluated the unconfined flowability of the produced SCC mixtures. **Figure 17** displays the test results together with the EFNARC specifica-

increases. Even with the reduction in the slump flow values, none of the CWP

It is noticed that the slump flow decreases as the amount of CWP in the mixture

*DOI: http://dx.doi.org/10.5772/intechopen.81842*

90 days of age.

tions [71].

**4.1 Slump flow results**

*\*\*w/cm = water/(cement + slag or CWP).*

#### **Table 6.**

*Mixtures' proportions for SCC (kg/m3 ).* *The Use of Ceramic Waste Powder (CWP) in Making Eco-Friendly Concretes DOI: http://dx.doi.org/10.5772/intechopen.81842*

conduct the compressive strength and the bulk electrical resistivity tests and the average results are used. **Figure 16** shows the different tests conducted. The microstructure development is judged by measuring the permeable pore volume at 28 and 90 days of age. Also, the pore system (i.e., total porosity and median pore diameter) is assessed using mercury intrusion porosimetry (MIP). The MIP is conducted at 90 days of age.

### **4.1 Slump flow results**

*Ceramic Materials - Synthesis, Characterization, Applications and Recycling*

Self-compacting concrete (SCC) has received wide attention and used in the construction industry worldwide since its development [59]. SCC is featured with high fluidity, and at the same time, high resistance to segregation and is placed purely under its weight without the need for vibration [60–62]. SCC properties are the result of modifying the composition of CVC by incorporating high powder content that has been mainly cement. However, the use of high cement content is not desirable as it will increase the cost and has other negative environmental effects. Replacing cement in SCC mixtures with waste powder is a trend gaining a great deal of attention with the growing awareness toward environmental protection and sustainable construction [63–70]. CWP is used to partially replace cement to produce

eco-friendly SCC. The cement content in the control mixture is 500 kg/m3

the preliminary mix design. The powder content of the control mixture meets the recommended value by EFNARC specifications [71]. The cement is partially replaced by the CWP in 20, 40 and 60% by weight. The concrete mixture is expected to yield compressive strength in the range of 80 MPa. The details of the mixtures' propor-

Ordinary Portland cement (OPC) is used as the main binder. The specific sur-

used as coarse aggregate. The specific gravity is 2.65 while the absorption was 0.7%. Natural sand with fineness modulus between 2.5 and 2.7 is used as fine aggregate.

Several tests are conducted to investigate the effect of replacing cement with CWP on the fresh properties of the produced concrete. Unconfined flowability of the produced SCC mixture is assessed by the slump flow test in accordance to ASTM C1611 [72]. Passing ability is evaluated through two tests namely the J-ring (i.e., ASTM C1621 [73]), and L-box. The segregation resistance is measured through conducting the GTM segregation column test conforming to ASTM C1610 [74]. Finally, the viscosity is measured by following the V-funnel test procedure described in the EFNARC specification [71]. On the other hand, compressive strength is performed at two test ages (i.e., 7 and 28 days) in order to evaluate the strength development. The durability characteristic is evaluated by conducting the bulk electrical resistivity as per ASTM C1760 [53] at 28 and 90 days of age. Triplicate samples are used to

**Mixture ingredients Mixture designation**

Cement 500 400 300 200 CWP 0 100 200 300 Water 175 175 175 175 Fine aggregate 871 871 871 871 Coarse aggregate 871 871 871 871 Super plasticizer 8.33 8.72 8.33 8.80 VMA\* 1.6 1.6 1.6 1.6 w/cm\*\* 0.35 0.35 0.35 0.35

/kg. Natural crushed stone of maximum size 9.5 mm is

**Control R-20 R-40 R-60**

based on

**4. Self-compacting concrete (SCC)**

tions are given in **Table 6**.

face area of cement is 380 m<sup>2</sup>

The specific gravity is 2.63.

**22**

**Table 6.**

*\**

*VMA = viscosity-modifying admixture. \*\*w/cm = water/(cement + slag or CWP).*

*Mixtures' proportions for SCC (kg/m3*

*).*

Slump flow test evaluated the unconfined flowability of the produced SCC mixtures. **Figure 17** displays the test results together with the EFNARC specifications [71].

It is noticed that the slump flow decreases as the amount of CWP in the mixture increases. Even with the reduction in the slump flow values, none of the CWP

**Figure 16.** *Different tests conducted on SCC.*

**Figure 17.** *Slump flow results.*

mixtures dropped to the slump flow class one (SF1) which is critical in the presence of highly congested reinforced concrete structures.

Chopra and Siddique [48] reported a similar trend when using rice husk ash (RHA) as cement replacement. The relatively higher specific surface area (SSA) of the CWP compared with cement would increase the water demand and accordingly resulted in lower slump flow values. Similarly, Sfikas et al. [75] reported a reduction in the slump flow of SCC when they used metakaolin, which is characterized by a high SSA, to replace cement.

The time taken for concrete to reach the 500 mm diameter circle on the steel base plate of the slump flow test is measured (T50). The T50 value can judge the viscosity of the SCC mixtures. High T50 values indicate mixtures with higher viscosity. The T50 results are given in **Table 7**.

### **4.2 J-ring results**

The passing ability of SCC is evaluated by the J-ring test. This test evaluates how the SCC mixtures can perform in the presence of reinforcing bars in form works. The difference between the unrestricted slump flow diameter and the J-ring flow diameter is shown in **Figure 18**. The inclusion of CWP improves the passing ability of the SCC mixtures. As the CWP content increases the mixtures' passing ability is improved and shows a great capacity for flowing through congested spaces. Therefore, mixtures containing high CWP perform better than the control mixture with regards to the passing ability.

## **4.3 L-box results**

The passing ability of SCC through congested reinforcement can also be assessed by using the L-box test. The L-box results are given in **Table 7**. Comparable blocking ratios are observed for all tested mixtures. The variation is less than 1.5%. SCC mixtures including CWP mixtures show no signs of blocking. Generally, EFNARC [71] suggests blocking risk is likely if the blocking ratio is below 0.8. The viscosity of the mixtures is too high if the blocking ratio is less than 0.8. This can cause blocking around highly congested sections. Based on the results, all mixtures with CWP can be used in applications where flow through congested reinforcement is needed.

### **4.4 V-funnel results**

In this test, the viscosity and filling ability of the fresh concrete is judged by the V-funnel test where the concrete is forced to flow through small cross sections and confined spaces. The flow rate (i.e., V-funnel time) of the SCC through the small cross-section is directly related to the mixture's viscosity.

The V-funnel test results are given in **Table 7**. The V-funnel results show an increasing trend, indicating a higher viscosity of the mixtures. All the measured


**25**

Ludwig [76].

**Figure 18.** *J-ring results.*

**4.6 Compressive strength results**

*The Use of Ceramic Waste Powder (CWP) in Making Eco-Friendly Concretes*

V-funnel time values correspond to the second viscosity class according to EFNARC specification [71]. The increase in the viscosity indicates an improvement in the segregation resistance. The viscosity-modifying admixture (VMA) is typically used to adjust mixtures' viscosity and enhance segregation resistance. Since the mixtures' viscosity values are significantly enhanced by the incorporation of CWP the VMA could be eliminated from the mixture or its dosage could be reduced. This would

The ability of concrete to remain homogeneous in the composition in its fresh state is defined as its segregation resistance. The GTM segregation column test is

Segregation percentage is shown in **Figure 19**. The segregation percentage decreases as the CWP content increases in the mixtures. The CWP significantly improves the segregation resistance of the SCC mixtures. The incorporation of CWP in SCC enhances the cohesiveness characteristics of the mixtures. The segregation percentages are below 15%, which shows that the SCC mixtures were superior regarding segregation resistance. Segregation resistance is related to viscosity. The improvement in segregation resistance is confirmed by the V-funnel test results. As the amount of CWP increases in the mixtures from 0 to 60%, the segregation resistance is enhanced by 72.5%. The substantial enhancement in the segregation resistance can be explained by the fact that the water adsorption of the CWP particles may induce suction forces possibly leading to cluster formation. This will lead to an increase in the inter-particle bonds as in the clustering theory enhancing the segregation resistance similar to RHA mixtures studied by Le and

Strength is measured at different test ages (7, 28, and 90 days) to evaluate the strength development as affected by the inclusion of CWP as partial cement replacement. The strength development due to the inclusion of any cement

*DOI: http://dx.doi.org/10.5772/intechopen.81842*

result in more economical and low-cost mixtures.

used to evaluate the mixtures' segregation resistance.

**4.5 GTM segregation column results**

**Table 7.**

*Fresh test results (modified from [42]).*

*The Use of Ceramic Waste Powder (CWP) in Making Eco-Friendly Concretes DOI: http://dx.doi.org/10.5772/intechopen.81842*

#### **Figure 18.** *J-ring results.*

*Ceramic Materials - Synthesis, Characterization, Applications and Recycling*

of highly congested reinforced concrete structures.

high SSA, to replace cement.

**4.2 J-ring results**

**4.3 L-box results**

**4.4 V-funnel results**

The T50 results are given in **Table 7**.

mixture with regards to the passing ability.

mixtures dropped to the slump flow class one (SF1) which is critical in the presence

Chopra and Siddique [48] reported a similar trend when using rice husk ash (RHA) as cement replacement. The relatively higher specific surface area (SSA) of the CWP compared with cement would increase the water demand and accordingly resulted in lower slump flow values. Similarly, Sfikas et al. [75] reported a reduction in the slump flow of SCC when they used metakaolin, which is characterized by a

The time taken for concrete to reach the 500 mm diameter circle on the steel base plate of the slump flow test is measured (T50). The T50 value can judge the viscosity of the SCC mixtures. High T50 values indicate mixtures with higher viscosity.

The passing ability of SCC is evaluated by the J-ring test. This test evaluates how the SCC mixtures can perform in the presence of reinforcing bars in form works. The difference between the unrestricted slump flow diameter and the J-ring flow diameter is shown in **Figure 18**. The inclusion of CWP improves the passing ability of the SCC mixtures. As the CWP content increases the mixtures' passing ability is improved and shows a great capacity for flowing through congested spaces. Therefore, mixtures containing high CWP perform better than the control

The passing ability of SCC through congested reinforcement can also be assessed by using the L-box test. The L-box results are given in **Table 7**. Comparable blocking ratios are observed for all tested mixtures. The variation is less than 1.5%. SCC mixtures including CWP mixtures show no signs of blocking. Generally, EFNARC [71] suggests blocking risk is likely if the blocking ratio is below 0.8. The viscosity of the mixtures is too high if the blocking ratio is less than 0.8. This can cause blocking around highly congested sections. Based on the results, all mixtures with CWP can be used in applications where flow through congested reinforcement is needed.

In this test, the viscosity and filling ability of the fresh concrete is judged by the V-funnel test where the concrete is forced to flow through small cross sections and confined spaces. The flow rate (i.e., V-funnel time) of the SCC through the small

The V-funnel test results are given in **Table 7**. The V-funnel results show an increasing trend, indicating a higher viscosity of the mixtures. All the measured

**Property measured Control R-20 R-40 R-60** T50 (seconds) 2.68 2.47 3.24 4.04 V-Funnel (seconds) 10.4 10.01 11 12.82 L-box ratio (H2/H1) 0.963 0.966 0.977 0.967

cross-section is directly related to the mixture's viscosity.

**24**

**Table 7.**

*Fresh test results (modified from [42]).*

V-funnel time values correspond to the second viscosity class according to EFNARC specification [71]. The increase in the viscosity indicates an improvement in the segregation resistance. The viscosity-modifying admixture (VMA) is typically used to adjust mixtures' viscosity and enhance segregation resistance. Since the mixtures' viscosity values are significantly enhanced by the incorporation of CWP the VMA could be eliminated from the mixture or its dosage could be reduced. This would result in more economical and low-cost mixtures.

### **4.5 GTM segregation column results**

The ability of concrete to remain homogeneous in the composition in its fresh state is defined as its segregation resistance. The GTM segregation column test is used to evaluate the mixtures' segregation resistance.

Segregation percentage is shown in **Figure 19**. The segregation percentage decreases as the CWP content increases in the mixtures. The CWP significantly improves the segregation resistance of the SCC mixtures. The incorporation of CWP in SCC enhances the cohesiveness characteristics of the mixtures. The segregation percentages are below 15%, which shows that the SCC mixtures were superior regarding segregation resistance. Segregation resistance is related to viscosity. The improvement in segregation resistance is confirmed by the V-funnel test results. As the amount of CWP increases in the mixtures from 0 to 60%, the segregation resistance is enhanced by 72.5%. The substantial enhancement in the segregation resistance can be explained by the fact that the water adsorption of the CWP particles may induce suction forces possibly leading to cluster formation. This will lead to an increase in the inter-particle bonds as in the clustering theory enhancing the segregation resistance similar to RHA mixtures studied by Le and Ludwig [76].
