**4.4 Cement mortars**

The used foundry sand can constitute as a raw material for the production of cement mortars efficiently. The use of used foundry sand can reduce the cost of the mortars to a considerable extent. Safi et al. [43] conducted experiments on selfcompacting mortars made with foundry sand wastes replacing normal sand at 0, 10, 30, and 50% and reported that self-compacting mortars incorporating foundry sand wastes yielded good results at 30% of foundry waste sand in place of normal sand. By the addition of used foundry sand, the workability of the cement mortars gets reduced. However, the deficiency in the workability can be made good by adding a superplasticizer at a low dosage. Cevik et al. [44] investigated the characteristics of cement mortars incorporating waste foundry sand from Turkey steel manufacturer as a partial substitute to natural sand at 0–60%. Based on the compressive strength tests conducted on samples at 3, 7, and 28 days, it is found that the optimum percentage substitution of used foundry sand as a replacement of natural sand in cement mortar is 15%, which yields the maximum compressive strength. Another research study on the use of calcium aluminate cement for recycling green sand and chemically bonded sand conducted by Navarro-Blasco et al. [45] confirmed that by using calcium aluminate cement, mortars of strength higher than 10 MPa can be produced with regular sand replaced by waste foundry sand at 50%.

## **4.5 Precast concrete products**

The used foundry sand can be incorporated in the concrete for the manufacture of precast concrete products like paver blocks and masonry blocks. Many researchers

**13**

given in **Table 1** for easy reference.

for paver blocks.

*A Review on the Usage of Recycled Sand in the Construction Industry*

conducted experiments on the applicability of used foundry sand in the production of paver blocks. Marchioni et al. [46] conducted experiments on paver blocks with spent foundry sand in Brazil. They reported that the paver blocks produced with 15% replacement of the fine aggregates with spent foundry sand gave acceptable strength parameters as per Brazilian standards ABNT NBR 9781. The incorporation of used foundry sand has shown a mixed response on the compressive strength of paver blocks. Kewal et al. [13] investigated the properties of paver blocks with geopolymer concrete incorporating used foundry sand and stated that the addition of used foundry decreases the compressive strength of paver blocks made with foundry sand-based geopolymer concrete. In another research on interlocking concrete paving blocks produced with foundry sand waste, Santos et al. [47] conducted compressive strength, measurement of dimension, and water absorption test paver blocks incorporating foundry sand waste. From the results, it is noted that the compressive strength of interlocking paver blocks produced with foundry sand waste is less than the compressive strength of paver blocks produced without foundry sand waste as per the specification laid by the Brazilian standards for the paver blocks. Tausif et al. [48], in a research study on foundry sand use in paver blocks, stated that paver blocks made with 12 mm maximum size coarse aggregate and 4.75 mm maximum size natural sand as fine aggregate with 0.3% synthetic fibers and foundry sand usage at 10% replacement of the fine aggregate showed a maximum compressive strength of 51.48 MPa at 28 days. In another research on the feasibility of used foundry sand in concrete pavers, Kulkarni and Katti [49] studied the properties of concrete pavers made with coarse aggregates of 10 mm maximum size and natural river sand as fine aggregate where the fine aggregates were replaced at 0, 25, 50, 75, and 100% with waste foundry sand from metal casting industries. Water absorption, compressive strength, split tensile strength, flexural strength, and abrasion resistance of the paver blocks were determined. From the test results, it is observed that water absorption increases with the percentage addition of waste foundry sand, whereas the compressive strength, splitting tensile strength, flexural strength, and abrasion resistance of paver blocks incorporating waste foundry sand decrease with the percentage addition of waste foundry sand. However, up to 50% replacements of natural river sand by waste foundry sand, the strength parameters of the paver blocks made are within the acceptable limits set forth by Indian Standard IS 15658

The waste foundry sand can be utilized in the production of masonry blocks also. Mahima et al. [50] studied compressive strength, water absorption, block density, drying shrinkage, and moisture movement of high-strength solid masonry blocks utilizing waste foundry sand as a replacement for fine aggregate and stated that at a replacement level of 20–30% of manufactured sand to waste foundry sand, the compressive strength and other parameters of the masonry blocks substantially improved over the regular masonry blocks. In this research, the control mix has a compressive strength of 23.78 MPa, whereas the blocks made with 20% fine aggregate replaced by used foundry sand yielded a compressive strength of 24.53 MPa. Naik et al. [51] studied the properties of concrete products like bricks, blocks, and paving stones incorporating recycled materials like used foundry sand, fly ash, and bottom ash. The brick samples were cast with regular sand, 9.5 mm maximum size crushed limestone chips, fly ash, bottom ash, and used foundry sand at 25 and 35% replacement of regular sand and tested for compressive strength, water absorption, density, and drying shrinkage. The test results confirmed that the concrete bricks with fine aggregates replaced with 25 and 35% ferrous green sand met with the compressive strength requirements as per ASTM C 55 for grade N concrete bricks. A summary of the research studies described for different applications above is

*DOI: http://dx.doi.org/10.5772/intechopen.92790*

#### *A Review on the Usage of Recycled Sand in the Construction Industry DOI: http://dx.doi.org/10.5772/intechopen.92790*

*Sandy Materials in Civil Engineering - Usage and Management*

slump of the fresh geopolymer concrete and compressive strength of hardened geopolymer concrete samples at 3rd day, 7th day, and 28th day and found that the optimum replacement percentage of foundry sand to the fine aggregate is 15% for the geopolymer concrete made of foundry sand, and the maximum compressive

The used foundry sand can constitute as a raw material for the production of cement mortars efficiently. The use of used foundry sand can reduce the cost of the mortars to a considerable extent. Safi et al. [43] conducted experiments on selfcompacting mortars made with foundry sand wastes replacing normal sand at 0, 10, 30, and 50% and reported that self-compacting mortars incorporating foundry sand wastes yielded good results at 30% of foundry waste sand in place of normal sand. By the addition of used foundry sand, the workability of the cement mortars gets reduced. However, the deficiency in the workability can be made good by adding a superplasticizer at a low dosage. Cevik et al. [44] investigated the characteristics of cement mortars incorporating waste foundry sand from Turkey steel manufacturer as a partial substitute to natural sand at 0–60%. Based on the compressive strength tests conducted on samples at 3, 7, and 28 days, it is found that the optimum percentage substitution of used foundry sand as a replacement of natural sand in cement mortar is 15%, which yields the maximum compressive strength. Another research study on the use of calcium aluminate cement for recycling green sand and chemically bonded sand conducted by Navarro-Blasco et al. [45] confirmed that by using calcium aluminate cement, mortars of strength higher than 10 MPa can be produced with regular sand replaced by waste foundry sand at 50%.

The used foundry sand can be incorporated in the concrete for the manufacture of precast concrete products like paver blocks and masonry blocks. Many researchers

strength obtained was 21.33 MPa.

*SEM image of concrete containing 100% FS.*

**4.5 Precast concrete products**

**4.4 Cement mortars**

**Figure 4.**

**12**

conducted experiments on the applicability of used foundry sand in the production of paver blocks. Marchioni et al. [46] conducted experiments on paver blocks with spent foundry sand in Brazil. They reported that the paver blocks produced with 15% replacement of the fine aggregates with spent foundry sand gave acceptable strength parameters as per Brazilian standards ABNT NBR 9781. The incorporation of used foundry sand has shown a mixed response on the compressive strength of paver blocks. Kewal et al. [13] investigated the properties of paver blocks with geopolymer concrete incorporating used foundry sand and stated that the addition of used foundry decreases the compressive strength of paver blocks made with foundry sand-based geopolymer concrete. In another research on interlocking concrete paving blocks produced with foundry sand waste, Santos et al. [47] conducted compressive strength, measurement of dimension, and water absorption test paver blocks incorporating foundry sand waste. From the results, it is noted that the compressive strength of interlocking paver blocks produced with foundry sand waste is less than the compressive strength of paver blocks produced without foundry sand waste as per the specification laid by the Brazilian standards for the paver blocks. Tausif et al. [48], in a research study on foundry sand use in paver blocks, stated that paver blocks made with 12 mm maximum size coarse aggregate and 4.75 mm maximum size natural sand as fine aggregate with 0.3% synthetic fibers and foundry sand usage at 10% replacement of the fine aggregate showed a maximum compressive strength of 51.48 MPa at 28 days. In another research on the feasibility of used foundry sand in concrete pavers, Kulkarni and Katti [49] studied the properties of concrete pavers made with coarse aggregates of 10 mm maximum size and natural river sand as fine aggregate where the fine aggregates were replaced at 0, 25, 50, 75, and 100% with waste foundry sand from metal casting industries. Water absorption, compressive strength, split tensile strength, flexural strength, and abrasion resistance of the paver blocks were determined. From the test results, it is observed that water absorption increases with the percentage addition of waste foundry sand, whereas the compressive strength, splitting tensile strength, flexural strength, and abrasion resistance of paver blocks incorporating waste foundry sand decrease with the percentage addition of waste foundry sand. However, up to 50% replacements of natural river sand by waste foundry sand, the strength parameters of the paver blocks made are within the acceptable limits set forth by Indian Standard IS 15658 for paver blocks.

The waste foundry sand can be utilized in the production of masonry blocks also. Mahima et al. [50] studied compressive strength, water absorption, block density, drying shrinkage, and moisture movement of high-strength solid masonry blocks utilizing waste foundry sand as a replacement for fine aggregate and stated that at a replacement level of 20–30% of manufactured sand to waste foundry sand, the compressive strength and other parameters of the masonry blocks substantially improved over the regular masonry blocks. In this research, the control mix has a compressive strength of 23.78 MPa, whereas the blocks made with 20% fine aggregate replaced by used foundry sand yielded a compressive strength of 24.53 MPa. Naik et al. [51] studied the properties of concrete products like bricks, blocks, and paving stones incorporating recycled materials like used foundry sand, fly ash, and bottom ash. The brick samples were cast with regular sand, 9.5 mm maximum size crushed limestone chips, fly ash, bottom ash, and used foundry sand at 25 and 35% replacement of regular sand and tested for compressive strength, water absorption, density, and drying shrinkage. The test results confirmed that the concrete bricks with fine aggregates replaced with 25 and 35% ferrous green sand met with the compressive strength requirements as per ASTM C 55 for grade N concrete bricks.

A summary of the research studies described for different applications above is given in **Table 1** for easy reference.


#### **Table 1.** *Summary of research studies.*
