**5.1 Consistency of mortars**

The slump of various mortars is evaluated according to the standard NF EN 1015-3. The test is mentioned in the **Figure 6**.

The results of consistency of different mortars are shown in **Figure 7**.

The figure shows that the increase in marble waste sand rate in the mortars increases slightly the consistency of the mortar. The maximum value is recorded by the mortar with 15%, with an increase of around 20% compared to that of the control mortar. This trend can be explained by the amount of fines present in the marble waste sand which enter the pores and thus release the trapped water, which results in better consistency.

**Figure 6.** *Consistency of mortar.*

pieces for acid attack tests **Figures 4** and **5**. Specimens produced from fresh mortar were demolded after 24 h and were then cured in water at 20 2°C until the date of the test. All tests are realized in the same conditions (laboratory conditions). The different compositions of the mixtures for the five formulations are given

**Notation Dune sand (g) Sea sand (g) Marble waste sand (g) Cement (g) Water (ml)** CM (0%) 675 675 0 450 252 M (5%) 641.25 641.25 67.5 450 252 M (10%) 607.5 607.5 135 450 252 M (15%) 573.75 573.75 202.5 450 252 M (20%) 540 540 270 450 252

in **Table 3**.

**Table 3.**

**38**

*Compositions of mixtures.*

**Figure 5.**

*Cubic test pieces (5 5 5).*

**Figure 4.**

*Prismatic test pieces (4 4 16).*

*Sandy Materials in Civil Engineering - Usage and Management*

**Figure 7.** *Variation of consistency versus substitution rate.*

#### **5.2 Density of mortars**

The density of various mortars is evaluated according to the standard NF EN 1015-6. The results of the density of mortars are shown in **Figure 8**.

compactness of the mixtures following the substitution of natural sand by marble

After 2, 7, 28 and 90 days of water curing, the 4 <sup>4</sup> 16 cm3 samples were used

At early ages (2 and 7 days), and through **Figure 10**, the compressive strengths

The compressive strength of specimens with marble waste sand at rates above 5% are better than that of the control mortar and the best gain is noted in the mixture of (20%) substitution rates. In fact, above 5% of the substitution rate of marble waste sand, all mortar compressive strengths are increasing, due to the increased compact-

for compressive and flexural tensile strength tests. The results are shown in

of mortars based on marble waste sand presented higher strength than that of control mortar, except for mortar with 5%. The best gain of compressive strength is of the order of 13.65 and 35.2%, it is recorded in the mixture of (20%) on the two deadlines respectively. These improvements in both levels can be explained by the presence of calcium carbonate [12, 13], which favor the creation of nucleation sites

**5.4 Compressive and flexural tensile strength of mortars**

*Introduction of Marble Waste Sand in the Composition of Mortar*

*DOI: http://dx.doi.org/10.5772/intechopen.91254*

*Change in air content as a function of the substitution rate.*

and hence the formation of calcium carbo-aluminates.

ness of mortars with less occluded air and constant W/C ratio [14].

waste sand [11].

**Figure 9.**

**Figure 10.**

**41**

*Effect of the substitution rate on the compressive strength.*

**Figures 10** and **11**, respectively.

The results show an increase in the density of all mortars. This growth is clearer with the increase in the rate of marble waste sand. The density values increase from 2.168 kg/m<sup>3</sup> for the reference mortar to 2.175, 2.192, 2.201, and 2.186 kg/m<sup>3</sup> for the mortars containing 5, 10, 15 and 20%. The increase in the density of the mortar to 15% of marble waste sand is around 1.52%. It is mainly due to the higher density of marble waste sand, which is higher than that of natural sand (dune sand and sea sand), and also to the retention of water by the grains of marble waste during the mixing.

**Figure 8.** *Variation of density versus substitution rate.*

#### **5.3 Air content**

The introduction of marble waste sand (**Figure 9**) leads to a decrease in the air content regardless of the substitution rate. The volume of occluded air decreases slightly from 7.4% for the reference mortar to 4.8% for the mortar incorporating 15% of marble waste sand. The significant reduction in the volume of air entrained in composite mortars of marble waste sand is related to the increase in the

*Introduction of Marble Waste Sand in the Composition of Mortar DOI: http://dx.doi.org/10.5772/intechopen.91254*

**Figure 9.**

**5.2 Density of mortars**

*Variation of consistency versus substitution rate.*

*Sandy Materials in Civil Engineering - Usage and Management*

mixing.

**Figure 7.**

**5.3 Air content**

*Variation of density versus substitution rate.*

**Figure 8.**

**40**

The density of various mortars is evaluated according to the standard NF EN

The results show an increase in the density of all mortars. This growth is clearer with the increase in the rate of marble waste sand. The density values increase from 2.168 kg/m<sup>3</sup> for the reference mortar to 2.175, 2.192, 2.201, and 2.186 kg/m<sup>3</sup> for the mortars containing 5, 10, 15 and 20%. The increase in the density of the mortar to 15% of marble waste sand is around 1.52%. It is mainly due to the higher density of marble waste sand, which is higher than that of natural sand (dune sand and sea sand), and also to the retention of water by the grains of marble waste during the

The introduction of marble waste sand (**Figure 9**) leads to a decrease in the air content regardless of the substitution rate. The volume of occluded air decreases slightly from 7.4% for the reference mortar to 4.8% for the mortar incorporating 15% of marble waste sand. The significant reduction in the volume of air entrained

in composite mortars of marble waste sand is related to the increase in the

1015-6. The results of the density of mortars are shown in **Figure 8**.

*Change in air content as a function of the substitution rate.*

compactness of the mixtures following the substitution of natural sand by marble waste sand [11].

#### **5.4 Compressive and flexural tensile strength of mortars**

After 2, 7, 28 and 90 days of water curing, the 4 <sup>4</sup> 16 cm3 samples were used for compressive and flexural tensile strength tests. The results are shown in **Figures 10** and **11**, respectively.

At early ages (2 and 7 days), and through **Figure 10**, the compressive strengths of mortars based on marble waste sand presented higher strength than that of control mortar, except for mortar with 5%. The best gain of compressive strength is of the order of 13.65 and 35.2%, it is recorded in the mixture of (20%) on the two deadlines respectively. These improvements in both levels can be explained by the presence of calcium carbonate [12, 13], which favor the creation of nucleation sites and hence the formation of calcium carbo-aluminates.

The compressive strength of specimens with marble waste sand at rates above 5% are better than that of the control mortar and the best gain is noted in the mixture of (20%) substitution rates. In fact, above 5% of the substitution rate of marble waste sand, all mortar compressive strengths are increasing, due to the increased compactness of mortars with less occluded air and constant W/C ratio [14].

**Figure 10.** *Effect of the substitution rate on the compressive strength.*

replacement, due to the height porosity of specimens with marble waste sand. Also, it can be assumed that that the matrix-sand interface of marble waste often gathers

*Introduction of Marble Waste Sand in the Composition of Mortar*

The results of the mass loss of the various mortars are presented in **Figure 13**. From the **Figure 13**, it is clear that the weight loss of mortars is influenced by the incorporation of marble waste sand. The values obtained are generally high compared to the control mortar. The optimum value is found in the 15% marble waste sand mortar. This is due to the departure of the water initially retained by the grains

The shrinkage test is carried out according to standard NF P 18-433, test is

pores thus increasing porosity.

*DOI: http://dx.doi.org/10.5772/intechopen.91254*

**5.6 Weight loss**

of the marble sand.

**5.7 Shrinkage**

**Figure 13.**

**Figure 14.**

**43**

*Shrinkage measurement on prismatic test piece.*

mentioned in **Figure 14**.

*Weight loss of different mortars.*

**Figure 11.** *Effect of the substitution rate on the flexural tensile strength.*

Generally, we note that the flexural tensile strengths of the mortars with marble waste sand, at all the ages (7, 28 and 90 days) are better than that of control mortar. The most significant value is achieved with the 20% mixture of marble waste sand, which presents a gains of 13.29, 22, 58 and 28% compared to the control mortar on the ages 2, 7, 28 and 90 days respectively. Two factors can explain these notations. Mortars based on marble waste sand contain quantities of fine particles, which favor granular stacking during mixing and thus causes an increase in flexural strength. However, the marble waste sand is characterized by more acute and porous grains, so that the bond with the cement paste of the mixture is better [7].

#### **5.5 Absorption by immersion**

The absorption of water by immersion is a property related to the durability of mortar, it allows estimating the volume of open pores of specimens by the penetration of water through the structure of these pores.

When the ratio of replacement of marble waste sand in mortar increased (**Figure 12**), there was an increase in water absorption, especially for the 20% of

**Figure 12.** *Absorption of water by immersion as a function of substitution rate.*

*Introduction of Marble Waste Sand in the Composition of Mortar DOI: http://dx.doi.org/10.5772/intechopen.91254*

replacement, due to the height porosity of specimens with marble waste sand. Also, it can be assumed that that the matrix-sand interface of marble waste often gathers pores thus increasing porosity.
