Comparative evaluation of mechanical performance of steel slag and earthen granular aggregates
Year 2023,
, 12 - 19, 31.03.2023
Aslı Yalçın Dayıoğlu
,
Mustafa Hatipoğlu
,
Ahmet Aydilek
Abstract
The diminishing quantity of natural resources has resulted in a search for alternative materials. Reusing industrial by-products, such as steel slag, provides opportunities for sustainable highway construction practices due to the valuable space they occupy and the potential environmental impacts when they are stockpiled. In this paper, the mechanical suitability of steel slag as an unbound highway aggregate is investigated, and its performance is compared with that of traditional graded aggregate base (GAB) materials. In order to compare the behavior, three steel slag samples with different aging properties and five aggregate samples from different quarries were employed. The results indicate that resilient moduli and permanent. Deformation characteristics of steel slag are comparable with those of traditional aggregates and can replace when used as a base or subbase course.
References
- [1] Dayioglu, A. Y., Aydilek, A. H., Cimen, O., & Ci men, M. (2018). Trace metal leaching from steel slag
used in structural fills. Journal of Geotechnical and
Geoenvironmental Engineering, 144(12), Article
04018089. [CrossRef]
- [2] Dayioglu, A. Y., & Aydilek, A. H. (2019). Effect of
pH and subgrade type on trace-metal leaching from
steel-slag embankments into groundwater. Journal
of Materials in Civil Engineering, 31(8), Article
04019149. [CrossRef]
- [3] US Geological Survey. (2021). Iron and steel slag
statitics. Miner. Commod. Summ. Slag-Iron Steel
Washington, DC., no. 703, pp. 86–87, 2021. https://www.usgs.gov/centers/national-minerals-informa tion-center/iron-and-steel-slag-statistics-and-infor mation
- [4] Tsakiridis, P. E., Papadimitriou, G. D., Tsivilis, S.,
& Koroneos, C. (2008). Utilization of steel slag for
Portland cement clinker production. Journal of
Hazardous Materials, 152(2), 805–811. [CrossRef]
- [5] Pellegrino, C., & Gaddo, V. (2009). Mechanical and
durability characteristics of concrete containing
EAF slag as aggregate. Cement and Concrete Com posites, 31(9), 663–671. [CrossRef]
- [6] Gao, J. T., Li, S. Q., Zhang, Y. T., Zhang, Y. L., Chen,
P. Y., & Shen, P. (2011). Process of re-resourcing of
converter slag. Journal of Iron and Steel Research In ternational, 18(12), 32–39. [CrossRef]
- [7] Brand, A. S., & Roesler, J. R. (2015). Steel furnace
slag aggregate expansion and hardened concrete
properties. Cement and Concrete Composites, 60,
1–9. [CrossRef]
- [8] Devi, V. S., & Gnanavel, B. K. (2014). Properties of
concrete manufactured using steel slag. Procedia
Engineering, 97, 95–104. [CrossRef]
- [9] Xue, P., He, D., Xu, A., Gu, Z., Yang, Q., Engström,
F., & Björkman, B. (2017). Modification of industrial
BOF slag: Formation of MgFe2O4 and recycling of
iron. Journal of Alloys and Compounds, 712, 640–
648. [CrossRef]
- [10] Li, Y., & Dai, W. B. (2018). Modifying hot slag and
converting it into value-added materials: a review.
Journal of Cleaner Production, 175, 176–189. [Cross Ref]
- [11] He, Z., Hu, X., & Chou, K. C. (2022). Synergetic
modification of industrial basic oxygen furnace slag
and copper slag for efficient iron recovery. Process
Safety and Environmental Protection, 165, 487–495.
[CrossRef]
- [12] Rohde, L., Peres Núñez, W., & Augusto Pereira Cer atti, J. (2003). Electric arc furnace steel slag: base material for low-volume roads. Transportation Re search Record, 1819(1), 201–207. [CrossRef]
- [13] Ahmedzade, P., & Sengoz, B. (2009). Evaluation of
steel slag coarse aggregate in hot mix asphalt con crete. Journal of Hazardous Materials, 165(1-3),
300–305. [CrossRef]
- [14] Pasetto, M., & Baldo, N. (2010). Experimental evalu ation of high performance base course and road base
asphalt concrete with electric arc furnace steel slags.
Journal of Hazardous Materials, 181(1-3), 938–948.
[CrossRef]
- [15] Amelian, S., Manian, M., Abtahi, S. M., & Goli, A.
(2018). Moisture sensitivity and mechanical perfor mance assessment of warm mix asphalt containing
by-product steel slag. Journal of Cleaner Produc tion, 176, 329–337. [CrossRef]
- [16] Liu, J., Xu, J., Liu, Q., Wang, S., & Yu, B. (2022). Steel
slag for roadway construction: a review of material
characteristics and application mechanisms. Jour nal of Materials in Civil Engineering, 34(6), Article
03122001. [CrossRef]
- [17] Ameri, M., & Behnood, A. (2012). Laboratory stud ies to investigate the properties of CIR mixes con taining steel slag as a substitute for virgin aggre gates. Construction and Building Materials, 26(1), 475–480. [CrossRef]
- [18] Maghool, F., Arulrajah, A., Du, Y. J., Horpibulsuk,
S., & Chinkulkijniwat, A. (2017). Environmental
impacts of utilizing waste steel slag aggregates as re cycled road construction materials. Clean Technol ogies and Environmental Policy, 19, 949–958. [Cross Ref]
- [19] Shi, C., & Day, R. L. (1999). Early strength develop ment and hydration of alkali-activated blast furnace slag/fly ash blends. Advances in Cement Research, 11(4), 189–196. [CrossRef]
- [20] Shi, C., & Qian, J. (2000). High performance ce menting materials from industrial slags—a review. Resources, Conservation and Recycling, 29(3), 195–
207. [CrossRef]
- [21] Wang, G., Wang, Y., & Gao, Z. (2010). Use of steel
slag as a granular material: Volume expansion pre diction and usability criteria. Journal of Hazardous
Materials, 184(1-3), 555–560. [CrossRef]
- [22] Ozkok, E., Davis, A. P., & Aydilek, A. H. (2016).
Treatment methods for mitigation of high alkalin ity in leachates of aged steel slag. Journal of Envi ronmental Engineering, 142(2), Article 04015063.
[CrossRef]
- [23] Dayioglu, A. Y., & Aydilek, A. H. (2017). Evaluation
of mitigation techniques for the expansive behavior
of steel slag. Geotechnical Frontiers 2017, 360–368. [CrossRef]
- [24] Stolle, D., Guo, P., & Liu, Y. (2009). Resilient modu lus properties of granular highway materials. Cana dian Journal of Civil Engineering, 36(4), 639–654.
[CrossRef]
- [25] Khogali, W. E., & Mohamed, E. H. H. (2004). Novel
approach for characterization of unbound materials.
Transportation Research Record, 1874(1), 38–46.
[CrossRef]
- [26] Mishra, D., & Tutumluer, E. (2012). Aggregate phys ical properties affecting modulus and deformation
characteristics of unsurfaced pavements. Journal of
Materials in Civil Engineering, 24(9), 1144–1152.
[CrossRef]
- [27] Haider, I., Kaya, Z., Cetin, A., Hatipoglu, M., Cetin,
B., & Aydilek, A. H. (2014). Drainage and mechan ical behavior of highway base materials. Journal of
Irrigation and Drainage Engineering, 140(6), Article
04014012. [CrossRef]
- [28] Hatipoglu, M., Cetin, B., & Aydilek, A. H. (2020).
Effects of fines content on hydraulic and mechanical
performance of unbound granular base aggregates.
Journal of Transportation Engineering, Part B: Pave ments, 146(1), Article 04019036. [CrossRef]
- [29] Tutumluer, E., & Pan, T. (2008). Aggregate morphol ogy affecting strength and permanent deformation
behavior of unbound aggregate materials. Journal
of Materials in Civil Engineering, 20(9), 617–627.
[CrossRef]
- [30] Kvasnak, A., West, R., Michael, J., Loria, L., Hajj,
E. Y., & Tran, N. (2010). Bulk specific gravity of re claimed asphalt pavement aggregate: Evaluating the
effect on voids in mineral aggregate. Transportation
Research Record, 2180(1), 30–35. [CrossRef]
- [31] Deniz, D., Tutumluer, E., & Popovics, J. S. (2010).
Evaluation of expansive characteristics of reclaimed
asphalt pavement and virgin aggregate used as base
materials. Transportation Research Record, 2167(1),
10–17. [CrossRef]
- [32] Yildirim, I. Z., & Prezzi, M. Chemical, mineralogi cal, and morphological properties of steel slag. Ad vences in Civil Engineering, 2011, Article 463638.
[CrossRef]
- [33] AASHTO M145-91. (2007). American Association
of State Highway and Transportation Officials. Clas sification of Soils and Soil-Aggregate Mixtures for
Highway Construction Purposes. Washington DC:
American Association of State Highway and Trans portation Officials.
- [34] Dayioglu, A. Y., Aydilek, A. H., & Cetin, B. (2014).
Preventing swelling and decreasing alkalinity of
steel slags used in highway infrastructures. Trans portation Research Record, 2401(1), 52–57. [Cross Ref]
- [35] AASHTO T 307-99. (2007). Standart Method of
Testing for: Determining the Resilient Modulus of
Soils and Aggregate Materials.” p. 40, https://www.scribd.com/document/378718757/2007-Stan dard-Method-of-Test-for-Determining-the-Resile int-Modulus-of-Soils-and-Aggregate-Materials#
- [36] R. G. Hicks. (2004). NCHRP 01-37 Guide for mech anistic-empirical design of new and rehabilitated pavement structures. National Cooperative High way Research Program 1-47A Report. Transporta tion Research Board, National Research Council,
Washington, DC.
- [37] Kancherla, A. (2004). Resilient modulus and perma nent deformation testing of unbound granular ma terials [Unpublished doctoral dissertation]. Texas
A&M University.
- [38] Witczak, M. W. (1998). Harmonized test methods
for laboratory determination of resilient modu lus for flexible pavement design (NCHRP Report
1-28A). National Cooperative Highway Research
Program Transportation Research Board National
Research Council.
- [39] Cetin, B., Aydilek, A. H., & Guney, Y. (2010). Sta bilization of recycled base materials with high car bon fly ash. Resources, Conservation and Recycling,
54(11), 878–892. [CrossRef]
- [40] Arulrajah, A., Piratheepan, J., Aatheesan, T., & Bo,
M. W. (2011). Geotechnical properties of recycled
crushed brick in pavement applications. Journal of
Materials in Civil Engineering, 23(10), 1444–1452.
[CrossRef]
- [41] Arulrajah, A., Piratheepan, J., Disfani, M. M., & Bo,
M. W. (2013). Resilient moduli response of recycled construction and demolition materials in pavement subbase applications. Journal of Materials in Civil Engineering, 25(12), 1920–1928. [CrossRef]
- [42] Patel, S., & Shahu, J. T. (2016). Resilient response and
permanent strain of steel slag-fly ash-dolime mix.
Journal of Materials in Civil Engineering, 28(10),
Article 04016106. [CrossRef]
- [43] Bestgen, J. O., Hatipoglu, M., Cetin, B., & Aydilek, A.
H. (2016). Mechanical and environmental suitabili ty of recycled concrete aggregate as a highway base
material. Journal of Materials in Civil Engineering,
28(9), Article 04016067. [CrossRef]
- [44] Sas, W., Głuchowski, A., Radziemska, M., Dzięcioł,
J., & Szymański, A. (2015). Environmental and ge otechnical assessment of the steel slags as a mate rial for road structure. Materials, 8(8), 4857–4875. [CrossRef]
- [45] Yoshida, N., Kimura, H., & Miyahara, T. (2010). Comparison of mechanical characteristics of slag
base-course materials produced by various iron and steel manufacturers in Japan. Proceedings of 11th international conference on asphalt pavements (pp. 2342-2352). International Society for Asphalt Pave ments.
- [46] Pacheco, L. G., & Nazarian, S. (2011). Impact of moisture content and density on stiffness-based ac ceptance of geomaterials. Transportation Research Record, 2212(1), 1–13. [CrossRef]
- [47] Xiao, Y., Tutumluer, E., Qian, Y., & Siekmeier, J. A. (2012). Gradation effects influencing mechanical
properties of aggregate base–granular subbase ma terials in Minnesota. Transportation Research Re cord, 2267(1), 14–26. [CrossRef]
Çelik cürufu ve doğal agregaların mekanik performansları üzerine karşılaştırmalı bir inceleme
Year 2023,
, 12 - 19, 31.03.2023
Aslı Yalçın Dayıoğlu
,
Mustafa Hatipoğlu
,
Ahmet Aydilek
Abstract
Doğal kaynakların gitgide tükenmesi, alternatif malzeme arayışlarını beraberinde getirmiştir. Çelik cürufu gibi endüstriyel yan ürünlerin yeniden kullanımı, kapladıkları değerli alan ve üst üste yığıldığında meydana gelebilecek olası çevresel etkileri nedeniyle sürdürülebilir otoyol inşaatı uygulamaları için fırsatlar sunmaktadır. Bu çalışmada, çelik cürufunun karayolu agregası olarak mekanik açıdan uygunluğu araştırılmış ve performansı geleneksel agrega malzemeleriyle karşılaştırılmıştır. Bu bağlamda farklı yaşlanma özelliklerine sahip üç adet çelik cürufu numunesi ve beş farklı ocaktan getirilen doğal agrega kullanılmıştır. Sonuçlar, çelik cürufunun esneklik modüllerinin ve kalıcı deformasyon özelliklerinin doğal agregalarınkilerle benzer mertebelerde olduğunu ve bir temel veya alt temel tabakası olarak söz konusu malzemelerin yerine kullanılabileceğini göstermektedir.
References
- [1] Dayioglu, A. Y., Aydilek, A. H., Cimen, O., & Ci men, M. (2018). Trace metal leaching from steel slag
used in structural fills. Journal of Geotechnical and
Geoenvironmental Engineering, 144(12), Article
04018089. [CrossRef]
- [2] Dayioglu, A. Y., & Aydilek, A. H. (2019). Effect of
pH and subgrade type on trace-metal leaching from
steel-slag embankments into groundwater. Journal
of Materials in Civil Engineering, 31(8), Article
04019149. [CrossRef]
- [3] US Geological Survey. (2021). Iron and steel slag
statitics. Miner. Commod. Summ. Slag-Iron Steel
Washington, DC., no. 703, pp. 86–87, 2021. https://www.usgs.gov/centers/national-minerals-informa tion-center/iron-and-steel-slag-statistics-and-infor mation
- [4] Tsakiridis, P. E., Papadimitriou, G. D., Tsivilis, S.,
& Koroneos, C. (2008). Utilization of steel slag for
Portland cement clinker production. Journal of
Hazardous Materials, 152(2), 805–811. [CrossRef]
- [5] Pellegrino, C., & Gaddo, V. (2009). Mechanical and
durability characteristics of concrete containing
EAF slag as aggregate. Cement and Concrete Com posites, 31(9), 663–671. [CrossRef]
- [6] Gao, J. T., Li, S. Q., Zhang, Y. T., Zhang, Y. L., Chen,
P. Y., & Shen, P. (2011). Process of re-resourcing of
converter slag. Journal of Iron and Steel Research In ternational, 18(12), 32–39. [CrossRef]
- [7] Brand, A. S., & Roesler, J. R. (2015). Steel furnace
slag aggregate expansion and hardened concrete
properties. Cement and Concrete Composites, 60,
1–9. [CrossRef]
- [8] Devi, V. S., & Gnanavel, B. K. (2014). Properties of
concrete manufactured using steel slag. Procedia
Engineering, 97, 95–104. [CrossRef]
- [9] Xue, P., He, D., Xu, A., Gu, Z., Yang, Q., Engström,
F., & Björkman, B. (2017). Modification of industrial
BOF slag: Formation of MgFe2O4 and recycling of
iron. Journal of Alloys and Compounds, 712, 640–
648. [CrossRef]
- [10] Li, Y., & Dai, W. B. (2018). Modifying hot slag and
converting it into value-added materials: a review.
Journal of Cleaner Production, 175, 176–189. [Cross Ref]
- [11] He, Z., Hu, X., & Chou, K. C. (2022). Synergetic
modification of industrial basic oxygen furnace slag
and copper slag for efficient iron recovery. Process
Safety and Environmental Protection, 165, 487–495.
[CrossRef]
- [12] Rohde, L., Peres Núñez, W., & Augusto Pereira Cer atti, J. (2003). Electric arc furnace steel slag: base material for low-volume roads. Transportation Re search Record, 1819(1), 201–207. [CrossRef]
- [13] Ahmedzade, P., & Sengoz, B. (2009). Evaluation of
steel slag coarse aggregate in hot mix asphalt con crete. Journal of Hazardous Materials, 165(1-3),
300–305. [CrossRef]
- [14] Pasetto, M., & Baldo, N. (2010). Experimental evalu ation of high performance base course and road base
asphalt concrete with electric arc furnace steel slags.
Journal of Hazardous Materials, 181(1-3), 938–948.
[CrossRef]
- [15] Amelian, S., Manian, M., Abtahi, S. M., & Goli, A.
(2018). Moisture sensitivity and mechanical perfor mance assessment of warm mix asphalt containing
by-product steel slag. Journal of Cleaner Produc tion, 176, 329–337. [CrossRef]
- [16] Liu, J., Xu, J., Liu, Q., Wang, S., & Yu, B. (2022). Steel
slag for roadway construction: a review of material
characteristics and application mechanisms. Jour nal of Materials in Civil Engineering, 34(6), Article
03122001. [CrossRef]
- [17] Ameri, M., & Behnood, A. (2012). Laboratory stud ies to investigate the properties of CIR mixes con taining steel slag as a substitute for virgin aggre gates. Construction and Building Materials, 26(1), 475–480. [CrossRef]
- [18] Maghool, F., Arulrajah, A., Du, Y. J., Horpibulsuk,
S., & Chinkulkijniwat, A. (2017). Environmental
impacts of utilizing waste steel slag aggregates as re cycled road construction materials. Clean Technol ogies and Environmental Policy, 19, 949–958. [Cross Ref]
- [19] Shi, C., & Day, R. L. (1999). Early strength develop ment and hydration of alkali-activated blast furnace slag/fly ash blends. Advances in Cement Research, 11(4), 189–196. [CrossRef]
- [20] Shi, C., & Qian, J. (2000). High performance ce menting materials from industrial slags—a review. Resources, Conservation and Recycling, 29(3), 195–
207. [CrossRef]
- [21] Wang, G., Wang, Y., & Gao, Z. (2010). Use of steel
slag as a granular material: Volume expansion pre diction and usability criteria. Journal of Hazardous
Materials, 184(1-3), 555–560. [CrossRef]
- [22] Ozkok, E., Davis, A. P., & Aydilek, A. H. (2016).
Treatment methods for mitigation of high alkalin ity in leachates of aged steel slag. Journal of Envi ronmental Engineering, 142(2), Article 04015063.
[CrossRef]
- [23] Dayioglu, A. Y., & Aydilek, A. H. (2017). Evaluation
of mitigation techniques for the expansive behavior
of steel slag. Geotechnical Frontiers 2017, 360–368. [CrossRef]
- [24] Stolle, D., Guo, P., & Liu, Y. (2009). Resilient modu lus properties of granular highway materials. Cana dian Journal of Civil Engineering, 36(4), 639–654.
[CrossRef]
- [25] Khogali, W. E., & Mohamed, E. H. H. (2004). Novel
approach for characterization of unbound materials.
Transportation Research Record, 1874(1), 38–46.
[CrossRef]
- [26] Mishra, D., & Tutumluer, E. (2012). Aggregate phys ical properties affecting modulus and deformation
characteristics of unsurfaced pavements. Journal of
Materials in Civil Engineering, 24(9), 1144–1152.
[CrossRef]
- [27] Haider, I., Kaya, Z., Cetin, A., Hatipoglu, M., Cetin,
B., & Aydilek, A. H. (2014). Drainage and mechan ical behavior of highway base materials. Journal of
Irrigation and Drainage Engineering, 140(6), Article
04014012. [CrossRef]
- [28] Hatipoglu, M., Cetin, B., & Aydilek, A. H. (2020).
Effects of fines content on hydraulic and mechanical
performance of unbound granular base aggregates.
Journal of Transportation Engineering, Part B: Pave ments, 146(1), Article 04019036. [CrossRef]
- [29] Tutumluer, E., & Pan, T. (2008). Aggregate morphol ogy affecting strength and permanent deformation
behavior of unbound aggregate materials. Journal
of Materials in Civil Engineering, 20(9), 617–627.
[CrossRef]
- [30] Kvasnak, A., West, R., Michael, J., Loria, L., Hajj,
E. Y., & Tran, N. (2010). Bulk specific gravity of re claimed asphalt pavement aggregate: Evaluating the
effect on voids in mineral aggregate. Transportation
Research Record, 2180(1), 30–35. [CrossRef]
- [31] Deniz, D., Tutumluer, E., & Popovics, J. S. (2010).
Evaluation of expansive characteristics of reclaimed
asphalt pavement and virgin aggregate used as base
materials. Transportation Research Record, 2167(1),
10–17. [CrossRef]
- [32] Yildirim, I. Z., & Prezzi, M. Chemical, mineralogi cal, and morphological properties of steel slag. Ad vences in Civil Engineering, 2011, Article 463638.
[CrossRef]
- [33] AASHTO M145-91. (2007). American Association
of State Highway and Transportation Officials. Clas sification of Soils and Soil-Aggregate Mixtures for
Highway Construction Purposes. Washington DC:
American Association of State Highway and Trans portation Officials.
- [34] Dayioglu, A. Y., Aydilek, A. H., & Cetin, B. (2014).
Preventing swelling and decreasing alkalinity of
steel slags used in highway infrastructures. Trans portation Research Record, 2401(1), 52–57. [Cross Ref]
- [35] AASHTO T 307-99. (2007). Standart Method of
Testing for: Determining the Resilient Modulus of
Soils and Aggregate Materials.” p. 40, https://www.scribd.com/document/378718757/2007-Stan dard-Method-of-Test-for-Determining-the-Resile int-Modulus-of-Soils-and-Aggregate-Materials#
- [36] R. G. Hicks. (2004). NCHRP 01-37 Guide for mech anistic-empirical design of new and rehabilitated pavement structures. National Cooperative High way Research Program 1-47A Report. Transporta tion Research Board, National Research Council,
Washington, DC.
- [37] Kancherla, A. (2004). Resilient modulus and perma nent deformation testing of unbound granular ma terials [Unpublished doctoral dissertation]. Texas
A&M University.
- [38] Witczak, M. W. (1998). Harmonized test methods
for laboratory determination of resilient modu lus for flexible pavement design (NCHRP Report
1-28A). National Cooperative Highway Research
Program Transportation Research Board National
Research Council.
- [39] Cetin, B., Aydilek, A. H., & Guney, Y. (2010). Sta bilization of recycled base materials with high car bon fly ash. Resources, Conservation and Recycling,
54(11), 878–892. [CrossRef]
- [40] Arulrajah, A., Piratheepan, J., Aatheesan, T., & Bo,
M. W. (2011). Geotechnical properties of recycled
crushed brick in pavement applications. Journal of
Materials in Civil Engineering, 23(10), 1444–1452.
[CrossRef]
- [41] Arulrajah, A., Piratheepan, J., Disfani, M. M., & Bo,
M. W. (2013). Resilient moduli response of recycled construction and demolition materials in pavement subbase applications. Journal of Materials in Civil Engineering, 25(12), 1920–1928. [CrossRef]
- [42] Patel, S., & Shahu, J. T. (2016). Resilient response and
permanent strain of steel slag-fly ash-dolime mix.
Journal of Materials in Civil Engineering, 28(10),
Article 04016106. [CrossRef]
- [43] Bestgen, J. O., Hatipoglu, M., Cetin, B., & Aydilek, A.
H. (2016). Mechanical and environmental suitabili ty of recycled concrete aggregate as a highway base
material. Journal of Materials in Civil Engineering,
28(9), Article 04016067. [CrossRef]
- [44] Sas, W., Głuchowski, A., Radziemska, M., Dzięcioł,
J., & Szymański, A. (2015). Environmental and ge otechnical assessment of the steel slags as a mate rial for road structure. Materials, 8(8), 4857–4875. [CrossRef]
- [45] Yoshida, N., Kimura, H., & Miyahara, T. (2010). Comparison of mechanical characteristics of slag
base-course materials produced by various iron and steel manufacturers in Japan. Proceedings of 11th international conference on asphalt pavements (pp. 2342-2352). International Society for Asphalt Pave ments.
- [46] Pacheco, L. G., & Nazarian, S. (2011). Impact of moisture content and density on stiffness-based ac ceptance of geomaterials. Transportation Research Record, 2212(1), 1–13. [CrossRef]
- [47] Xiao, Y., Tutumluer, E., Qian, Y., & Siekmeier, J. A. (2012). Gradation effects influencing mechanical
properties of aggregate base–granular subbase ma terials in Minnesota. Transportation Research Re cord, 2267(1), 14–26. [CrossRef]