Effect of processing on the rheological properties of poly-urethane/urea bituminous products

Carrera, Virginia; Partal, P.; García‐Morales, M.; Gallegos, C.; Pérez-Lepe, A.

doi:10.1016/j.fuproc.2010.03.028

Cited by 64 publications

(41 citation statements)

References 17 publications

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“…These two features, which increase as curing time does, point out the development of a more "solid-like" microstructure, if compared to the corresponding neat bitumen or "non-treated" sample [19]. Figure 1 demonstrates that, even with no curing, the neat bitumen experiences a clear increase in viscosity after the addition of 2 wt.% MDI-CO. As reported by Carrera et al [20], a fraction of the -NCO groups in the prepolymer chains (functionality between 2 and 3) is known to react, during its blending with bitumen, with -OH pendant groups present in the most polar molecules of bitumen (asphaltenic regions). Hence, the resulting urethane linkages,…”

Section: Study On the Modification Degree Through Viscous Flow Testsmentioning

confidence: 81%

“…-10 -Consequently, reactions 2 and 3 are expected to build up a more compact microstructure, through the formation of urea linkages between smaller units which, as commented, still had reactive -NCO sites available [17,20].…”

Section: Study On the Modification Degree Through Viscous Flow Testsmentioning

confidence: 99%

“…Figure 7 shows the evolution of the "modified" colloidal index values for the modified binders studied. According to the C.I.mod defined above and to the bitumen colloidal model, a higher index value would be related to a material which exhibits a more significant solid-like behaviour [20,23,26,27]. Longer curing times, above all after only 1h of processing, enhance the material's microstructure (larger quality of its colloidal microstructure or a more solid-like behaviour).…”

Section: Chemical Modification and Microstructurementioning

confidence: 99%

“…Bitumen modification with this type of prepolymer is expected to take place by reaction of the free -NCO groups in the prepolymer and bitumen pendant groups which contain active atoms (-OH mainly, typically present in the asphaltenes) [16,17]. However, previous studies on NCO-functionalized polyether prepolymers [18][19][20] point out that this type of bitumen modification is a complex process, greatly influenced by a post-process curing which involves ambient moisture. Thus, during the material's service-life, water from the air is able to slowly diffuse into bitumen and react with -NCO groups in excess ("ambient" modification).…”

Section: Introductionmentioning

confidence: 99%

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Processing of bitumens modified by a bio-oil-derived polyurethane

Cuadri¹,

García‐Morales²,

Navarro³

et al. 2014

Fuel

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Castor oil (CO) functionalized by isocyanate groups (-NCO) is proposed as a novel bio-based reactive polyurethane (PU) for bitumen modification. This work presents a comparative analysis conducted on blends of bitumen and 2 wt.% of a PU prepolymer prepared by NCO-functionalization of castor oil. Four preparation procedures were evaluated, which resulted from the combination of two processing times (1h or 24h, at 90ºC) followed by two different post-treatments (water addition or ambient curing for up to 6 months). It was found that the degree of modification attained after posttreatment depends on the previous processing conditions. Thus, short processing times are required if the binder is further subjected to ambient curing. Instead, the success of the water-addition modification falls on a previous long processing step. As revealed by rheological tests, ambient curing was seen to be by far a more efficient way of modification if compared to direct addition of water, and makes clear that the resulting binder evolves towards a better performance when in service. In that sense, Thin Layer Chromatography tests, Modulated DSC and AFM images demonstrated a more complex microstructure characterized by the presence of a larger content of molecules with higher polarity, size and molecular weight.

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Section: Study On the Modification Degree Through Viscous Flow Testsmentioning

confidence: 81%

Section: Study On the Modification Degree Through Viscous Flow Testsmentioning

confidence: 99%

Section: Chemical Modification and Microstructurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Processing of bitumens modified by a bio-oil-derived polyurethane

Cuadri¹,

García‐Morales²,

Navarro³

et al. 2014

Fuel

Self Cite

View full text Add to dashboard Cite

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“…-12 -Consequently, reactions 2 and 3 are expected to build up a more compact microstructure, through the formation of urea linkages between smaller units which, as commented, still had reactive -NCO sites available [25,26,33,34]. In addition, the Carreau's model fittings (see Table 4) reveal the development of a more complex microstructure for the "MDI-binder", as deduced from a higher value of viscosity (0) along with a lower value of the threshold shear rate c γ  (i.e.…”

Section: Rheological Behaviour At High In-service Temperaturesmentioning

confidence: 99%

Chemically modified bitumens with enhanced rheology and adhesion properties to siliceous aggregates

Cuadri¹,

Partal²,

Ahmad

et al. 2015

Construction and Building Materials

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Moisture damage is one of the major premature failures that worsens the performance and shortens service life of pavements. This research assesses the effect that two chemical modifiers (thiourea and an isocyanate-functionalized castor oil prepolymer) exerts on the bitumen rheology and on the resistance to potential moisture damage of asphalt mixtures based on siliceous aggregates. Both thiourea and the isocyanate-based prepolymer improve the viscous and viscoelastic behaviours of bitumen at high inservice temperatures, particularly the isocyanate-based reactive modifier. Likewise, the visual inspection of the degree of bitumen coating on loose mixtures exposed to water in a "rolling bottle" test, and further surface free energy measurements, showed that the bitumen modification by the isocyanate-based prepolymer seems to reduce moistureinduced damage on siliceous aggregates. Conversely, thiourea-based modification increases sensitivity of the bitumen-aggregate mixture to water. Different adhesion mechanisms, based on chemical or physical bonds with the aggregate surface, have been proposed for each modifier.

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Review on Mechanisms of Bitumen Modification: Process and Variables

Bhagat

Ranadive

2022

Recent Trends in Construction Technology and Management

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Effect of processing on the rheological properties of poly-urethane/urea bituminous products

Cited by 64 publications

References 17 publications

Processing of bitumens modified by a bio-oil-derived polyurethane

Processing of bitumens modified by a bio-oil-derived polyurethane

Chemically modified bitumens with enhanced rheology and adhesion properties to siliceous aggregates

Review on Mechanisms of Bitumen Modification: Process and Variables

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