**4.1 Characterisation of materials**

**Figure 2** indicates the result of XRD analysis for WFS filler. As shown in the figure, WFS is essentially formed by quartz mineral, as expected. **Table 4** shows the composition of the main oxides present in the WFS filler obtained by XRF analysis. The high percentage of silica confirms the XRD analysis of the material [8, 16, 17]. **Table 6** indicates the physical characteristics of the aggregates. WFS aggregate apparent specific gravity of WFS is very close to conventional aggregates (pebble and sand) [7, 9, 10, 13] each other except for PC. Pebble had a Los Angeles abrasion loss below the maximum allowed by the Brazilian standard, which is 50%. The WFS had 76.25% of its particle sizes passing at #200 sieve and are slightly larger than that of Portland cement, i.e. it is too fine to replace part of the fine aggregate of the asphalt mixes [8, 10, 12], thus demonstrating that the residue could only replace part or total filler fraction.

**Table 7** shows the resulting granulometric composition of the mineral aggregates with and without the addition of WFS. It is observed that all the mixtures were composed with the same amount of aggregates, varying only the proportion between the two types of the filler fraction. Conventional mixture 1 used PC exclusively, while mixture 2 used WFS as filler exclusively. The other mixtures had variations between permutations of PC and WFS proportions. The grain size distribution of the mineral aggregates, the "C" range maximum and minimum limits of the Brazilian highway specification and the resulting aggregates of mixtures 1 and 2 are shown in **Figure 5**.


*Notes: d90, d50 and d10 are the particle size for which 90, 50 and 10% of the all particles, in mass, are finer than it.*

### **Table 6.**

*Physical characteristics of aggregates.*


### **Table 7.**

*Granulometric composition of mineral aggregate mixtures with and without WFS addition.*

**Figure 5.** *Grain size distribution and limit curves of mineral aggregates.*

#### **4.2 Physical characteristics of mixtures**

**Figure 3** shows the main physical parameters of the mixtures, obtained through the Marshall methodology. OAC values of the mixtures containing WFS are comparable to the control in mixture 1 [14, 17]. Mixture 1 obtained the lowest OAC (4.5%), whereas mixtures with WFS had little bit higher OAC values, whose contents increased as WFS proportions were increased too [13]. This reason probably is due to the absorption characteristics of this residue, and not due to the grain size [10, 32], since CP has larger particle size and therefore smaller surface area and thus should consume less AC, at the same proportion of WFS.

It was observed that all five mixtures met the Brazilian standards regarding the physical Marshall parameters (OAC, AVV, VMA and AVR). Mixture 1 had a higher GMB values than all other mixtures with WFS and was therefore the densest. The other mixtures maintained a slight decrease of this parameter, when the proportion of WFS in the mixture was increased [7, 9, 13]. Mixture 2 (100% WFS filler) had the highest amount of AVV and the second largest AVR among all mixtures. AVV values increased when WFS content were increased in the mixtures [8–10, 32].

#### **4.3 Mechanical characteristics of mixtures**

High amounts of AVV and AVR tend to negatively influence STA and FLV values, given the viscous characteristic of AC. Thus, mixture 1 showed the best performance,

**61**

**Figure 6.**

*(c) RM/ITS ratio and (d) total strain (static creep).*

*Use of Waste Foundry Sand (WFS) as Filler in Hot-Mixed Asphalt Concrete*

apparent correlation between AVV and static ITS values (**Figure 6**).

with the highest STA and lowest FLV values. Among the mixtures using WFS, mixture 5 (one fourth WFS + three fourths PC) was the one that presented the highest value of GMB, thus being the densest, and also presented the highest value of STA; however, it had the highest FLV value too. The FLV values of the WFS blends were higher than the PC blends, which characterises a higher AC consumption of these blends. In summary, the use of WFS decreased the stability of blends [6, 8, 10, 12, 32] while increasing their fluency. This latter is in disagreement with that observed by the author cited previously. Even so, all mixtures showed STA values higher than the minimum required (>5 kN). There was a certain tendency that static ITS values will decrease as WFS content increased [7, 9, 10, 13, 32]. Mixtures 3 and 5 presented higher values of this parameter than control mixture 1 [25]. All asphalt mixtures presented values above the minimum value of the Brazilian standard (>0.65 MPa). This is a good indication for durability of the mixtures since fatigue life is a function of ITS. There was not an

The use of WFS decreased the RM values. Mixture 1 presented the highest value, followed by mixture 2. In Brazil, the relationship between RM and static ITS (RM/ ITS) has been used as an analysis parameter to evaluate the behaviour of asphalt mixtures related to fatigue life. As a rule, mixtures with RM/ITS ratio around 3000

*Mechanical characteristics of studied mixtures: (a) static indirect tensile strength, (b) resilient modulus,* 

*DOI: http://dx.doi.org/10.5772/intechopen.89715*

#### *Use of Waste Foundry Sand (WFS) as Filler in Hot-Mixed Asphalt Concrete DOI: http://dx.doi.org/10.5772/intechopen.89715*

*Sandy Materials in Civil Engineering - Usage and Management*

**4.2 Physical characteristics of mixtures**

*Grain size distribution and limit curves of mineral aggregates.*

**4.3 Mechanical characteristics of mixtures**

**Figure 3** shows the main physical parameters of the mixtures, obtained through the Marshall methodology. OAC values of the mixtures containing WFS are comparable to the control in mixture 1 [14, 17]. Mixture 1 obtained the lowest OAC (4.5%), whereas mixtures with WFS had little bit higher OAC values, whose contents increased as WFS proportions were increased too [13]. This reason probably is due to the absorption characteristics of this residue, and not due to the grain size [10, 32], since CP has larger particle size and therefore smaller surface area and

It was observed that all five mixtures met the Brazilian standards regarding the physical Marshall parameters (OAC, AVV, VMA and AVR). Mixture 1 had a higher GMB values than all other mixtures with WFS and was therefore the densest. The other mixtures maintained a slight decrease of this parameter, when the proportion of WFS in the mixture was increased [7, 9, 13]. Mixture 2 (100% WFS filler) had the highest amount of AVV and the second largest AVR among all mixtures. AVV values increased when WFS content were increased in the mixtures [8–10, 32].

High amounts of AVV and AVR tend to negatively influence STA and FLV values, given the viscous characteristic of AC. Thus, mixture 1 showed the best performance,

thus should consume less AC, at the same proportion of WFS.

**60**

**Figure 5.**

with the highest STA and lowest FLV values. Among the mixtures using WFS, mixture 5 (one fourth WFS + three fourths PC) was the one that presented the highest value of GMB, thus being the densest, and also presented the highest value of STA; however, it had the highest FLV value too. The FLV values of the WFS blends were higher than the PC blends, which characterises a higher AC consumption of these blends. In summary, the use of WFS decreased the stability of blends [6, 8, 10, 12, 32] while increasing their fluency. This latter is in disagreement with that observed by the author cited previously. Even so, all mixtures showed STA values higher than the minimum required (>5 kN).

There was a certain tendency that static ITS values will decrease as WFS content increased [7, 9, 10, 13, 32]. Mixtures 3 and 5 presented higher values of this parameter than control mixture 1 [25]. All asphalt mixtures presented values above the minimum value of the Brazilian standard (>0.65 MPa). This is a good indication for durability of the mixtures since fatigue life is a function of ITS. There was not an apparent correlation between AVV and static ITS values (**Figure 6**).

The use of WFS decreased the RM values. Mixture 1 presented the highest value, followed by mixture 2. In Brazil, the relationship between RM and static ITS (RM/ ITS) has been used as an analysis parameter to evaluate the behaviour of asphalt mixtures related to fatigue life. As a rule, mixtures with RM/ITS ratio around 3000

**Figure 6.**

*Mechanical characteristics of studied mixtures: (a) static indirect tensile strength, (b) resilient modulus, (c) RM/ITS ratio and (d) total strain (static creep).*

exhibit good structural behaviour because they allow the use of thinner asphalt wearing layers for the same fatigue life; that is, they characterise mixtures that are not susceptible to early development of permanent deformations because they are not rigid enough. In this sense, mixture 3 was the only one that met this criterion. On the other hand, the conventional mixture 1 presented the highest value of this ratio, thus indicating a more rigid behaviour.

**Figure 7** shows the comparison between asphalt mixtures in relation to the stress-controlled fatigue test. For the acquisition of fatigue curves, the average value of the RM and the static ITS of each mixture were used. Between Mixtures 1 and 4, the best-fitting straight lines were very close to each other, with a parallelism between the line slopes, and both mixtures can be considered to have practically the same fatigue life. Mixture 2 presented the shortest fatigue life, while mixture 5 presented the longest fatigue life, standing out among the others. For applied stress differences up to 0.4 MPa, Mixtures 1, 2 and 4 behave similarly.

It should be noted that mixture 5 presented the second best ITS result and the second closest value of the RM/ITS ratio around 3000, thus justifying the use of this parameter as a quantitative indicator of fatigue life of asphalt mixtures. The fatigue life test on mixture 3 was not performed.

Regarding the permanent deformation, Mixtures 2 and 3 presented lower values than mixture 1, while mixture 5 presented the highest value among the others. There was no direct relationship with AVV, since, of all of them, mixture 5 presented the lowest value of voids. Mixture 3 presented the lowest value of permanent deformation, confirming again the good indicative of the RM/ITS ratio around 3000 in predicting the behaviour of asphalt mixtures for fatigue and permanent deformations. All mixtures presented permanent deformation values below the

**63**

Brazil

*Use of Waste Foundry Sand (WFS) as Filler in Hot-Mixed Asphalt Concrete*

conventional criterion of 0.020 mm/mm and do not have the tendency to be suscep-

This work analysed five asphalt mixtures, one using 100% CP as a filler and the other four using WFS, with a maximum proportion of 5% (by weight) of the total aggregate. The WFS residue used consisted of almost 94% silica, without organic compounds, with apparent specific gravity similar to clean sand and slightly coarser

All mixtures with WFS residue presented physical and mechanical parameters within the Brazilian standards, following the Marshall methodology, although with lower STA and higher FLV values. The use of WFS increased static ITS values, while decreased MR values. The mixtures with WFS showed total permanent deformation values less than 2% after 75 min of the test. The RM/ITS ratio around 3000 proved to be a good indication of mixtures with better performance against fatigue life and

Finally, the use of WFS as a mineral filer in asphalt mixtures proved to be adequate, meeting the criteria of Brazilian standards in physical and mechanical tests.

The authors would like to thank Prof. Dr. Laura Maria Goretti da Mota, from Pavement Laboratory of COPPE/Federal University of Rio de Janeiro (UFRJ), for some laboratorial tests carried out in that place. This work was supported by the

\*, Karine Jussara Sá da Costa2

1 Master Science Program in Civil Engineering, Federal University of Amazonas,

2 Department of Civil Engineering, Federal University of Roraima, Boa Vista, RR,

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Raimundo Kennedy Vieira1

CNPq [grant number 620244/2008-9]; FAPEAM [scholarship].

\*Address all correspondence to: ncampelo@ufam.edu.br

provided the original work is properly cited.

*DOI: http://dx.doi.org/10.5772/intechopen.89715*

**5. Conclusions**

permanent deformation.

**Acknowledgements**

**Author details**

Manaus, AM, Brazil

Nilton de Souza Campelo1

and Adalena Kennedy Vieira1

than CP.

tible to premature permanent deformations.

**Figure 7.** *Fatigue life for the mixtures with and without WFS content.*

conventional criterion of 0.020 mm/mm and do not have the tendency to be susceptible to premature permanent deformations.
