RESUMO
Nowadays, an increasing amount of reclaimed asphalt pavement (RAP) is being produced from the reconstruction and/or modernisation of asphalt pavements. It is necessary to recycle the obtained RAP according to principles of sustainable development. Therefore, this work includes the design of asphalt mixtures containing RAP with bio-derived modifier and evaluates their performance properties. Crosslinked sodium alginate was applied for bitumen modification. The studies were carried out for four different modifier contents, i.e., 1.0%, 2.5%, 4.0% and 5.5%, with and without crosslinking agent. On the basis of the binder test results, the optimal amount of the additive was found to be 2.5%. The nanostructure analysis for the base and modified binders indicated a dual crosslinked biopolymer effect. As a result of the bee structure size decrease, the binder softening effect was observed. The asphalt mix properties showed that application of biopolymer-modified binder is fully justified due to the functional parameters of the mixture, especially the increased resistance to water and frost by about 9%.
RESUMO
Destructive corrosion processes lead to the loss of primary mechanical properties of metal construction materials, which generates additional costs during their maintenance connected with repairs and protection. The effectiveness of corrosion inhibitors can be determined by using many methods, in particular quantum chemical modeling. The subject of the theoretical analyses presented in this work involves the anticorrosion properties of amines with various chemical structures. Evaluation of the corrosion inhibition properties of selected amines was performed on the basis of the HOMO-LUMO energy gap, dipole moment (µ), electronegativity (χ) determined as a result of the energy of the highest occupied molecular orbital (HOMO) and the energy of the lowest unoccupied molecular orbital (LUMO). Moreover, the HSAB (Hard and Soft Acids and Bases) theory was used to explain the reactivity of the analyzed amines, while the Mulliken population analysis was used to determine their electrostatic interactions with the surface of protected metal. The obtained results indicate that the protonation reaction of aliphatic amines leads to a change in the nature of the formation of a coordination bond with the surface of the protected metal. In turn, the quantum chemical calculations showed that the protonation reaction of aliphatic amines leads to a decrease in their corrosion inhibition efficiency. Most of the analyzed parameters indicated that tertiary amines are characterized by the highest corrosion inhibition efficiency.
RESUMO
Brick debris is one of the main construction wastes obtained from demolition of buildings. However, this material can be successfully used in the recycling process. The purpose of the study was to determine the brick dust addition effect on asphalt surface service life. An asphalt concrete reference mix was designed for bonding layer and prepared using a Marshall compacting device. In addition, three mixes with combined lime-brick filler were prepared as well as one mix containing only brick filler. The samples were tested for their volumetric properties-density, bulk density, air void content, resistance to water and frost and stiffness modulus with varying test temperatures. It was found that 25% of brick dust addition to the filler did not considerably change the properties of the tested samples, while in the case of 50% filler the replacement stiffness and frost resistance decrease; however, the minimum required value is maintained. It can be concluded that the lime filler can be replaced with up to 50% of brick dust without a negative impact on the properties of asphalt mix. The proposed solution fits into the idea of sustainable development indicating a way of brick debris management.
RESUMO
Compaction index is one of the most important technological parameters during asphalt pavement construction which may be negatively affected by wrong asphalt paving machine set, weather conditions, or the mix temperature. Presented laboratory study analyzes the asphalt mix properties in case of inappropriate compaction. The reference mix was designed for AC 11 S wearing layer (asphalt concrete for wearing layer with maximum grading of 11 mm). Asphalt mix samples used in the tests were prepared using Marshall device with the compaction energy of 2 × 20, 2 × 35, 2 × 50, and 2 × 75 blows as well as in a roller compactor where the slabs were compacted to various heights: 69.3 mm (+10% of nominal height), 66.2 mm (+5%), 63 mm (nominal), and 59.9 mm (-5%) which resulted in different compaction indexes. Afterwards the samples were cored from the slabs. Both Marshall samples and cores were tested for air void content, stiffness modulus in three temperatures, indirect tensile strength, and resistance to water and frost indicated by ITSR value. It was found that either insufficient or excessive level of compaction can cause negative effect on the road surface performance.
RESUMO
Zeolite materials are used in the warm mix asphalt technology as an asphalt foaming additive, which partially replaces the filler. This article analyzes the influence of the zeolite and other fillers addition on the properties of mastic asphalt. In the research, 35/50 penetration grade asphalt and three types of fillers were used: lime filler (L), zeolite tuff (clinoptilolite) (C), hydrated lime (H) and their mixed combinations (C:L in 1:1 and 1:3 proportions as well as C:L:H in 2:2:1 ratio). The characteristics of the materials included: chemical analysis, phase composition and particle size distribution. The following properties were determined on the asphalt mastic samples: penetration, softening point, penetration index, dynamic viscosity and stiffening measured by softening point increase. It was found that clinoptilolite could partially replace the traditional lime filler, without a negative impact on the asphalt mastic properties. Additionally, the hydrated lime inclusion should have a positive effect on the frost resistance of an asphalt mix.
RESUMO
The previous studies on asphalt mix and asphalt with waste engine oil addition indicate the possibility of using this type of waste material for the construction of road pavements. The research presented in this paper aimed at the preliminary assessment of possible waste engine oil (WEO) addition to the asphalts foamed with water-soaked zeolites. In this research, synthetic zeolite Na-P1 and natural clinoptilolite were used. In order to improve the foaming effect, the zeolites were soaked with water before dispensing to the asphalt, in the amount of 75% asphalt weight for Na-P1 and 25% for clinoptilolite. The tests were performed for one type of waste engine oil-5W40 and two type of binders: 20/30 and polymer modified 25/55-60. The asphalt parameters such as the dynamic viscosity, penetration and softening point were determined with the addition of WEO and zeolites in the concentration of 0%, 3%, 5%, 7% for both materials. It was found that the WEO addition lowers the viscosity and softening point of asphalt but increases penetration. The zeolite addition affected the change of these parameters to a minor extent or was statistically irrelevant. The chemical analysis of the asphalt samples with WEO addition performed with the X-ray Fluorescence method did not show a significant amount of heavy metals which would increase the probability of low-temperature cracking. The analysis of the results indicates the possibility of using zeolite-foamed asphalt technology with WEO addition.
RESUMO
In recent years, numerous studies have been carried out on new technologies allowing to reduce of mix asphalt production temperatures. One of the possibilities is to foam the asphalt with "water-containing" additives, which include zeolites. So far, mainly synthetic zeolites of the Linde A structure type, obtained from chemical reagents, and natural clinoptilolite have been used in WMA technology. In this studies, the synthetic zeolites produced from fly ashes with 4 different types of crystalline structure were analyzed. Zeolite materials were characterized by textural parameters and thermal analysis. The amount of zeolite added to asphalt was 0, 3, 5, 7 wt % in relation to the weight of asphalt. Determination of dynamic viscosity was performed at two temperatures: 135 and 160 and 4 time intervals. The tests were performed for two asphalt binders: 35/50 and 100/150 penetration grade. As a conclusion, it was found that the viscosity of asphalt pastes with zeolitic materials increases with the increase in the amount of zeolite added. The increase level depends mainly on the textural parameters. The potential usefulness of fly ash derived zeolites in the process of asphalt foaming, which depends mainly on the amount of water contained in the zeolite structure and the method of its release, has been proved.
