Wyniki wyszukiwania - BazTech

1

Water absorption kinetics of bitumen modified cement mortars

Trykoz Liudmyla, Rezunenko Maryna, Pustovoitova Oksana, Semenova-Kulish Victoria, Borodin Dmytro

Roads and Bridges - Drogi i Mosty

|

2022

|

Vol. 21, no. 2

167--178

EN

Concrete permeability is a major factor that affects durability and reliability of structures – bridges, tunnels, culvert pipes, etc. It is important to identify effective methods of protection of such structures against water penetration, for example by using a modifying substance. Samples of cement mortar composites were used for water absorption simulation. Bitumen emulsion was used as a modifying agent. According to the water absorption kinetics, the following parameters of the pore microstructure of the mortar composite were estimated: the index of mean size of open capillary pores, closed porosity, and the index of size uniformity. The research has shown that the addition of bitumen emulsion decreases the pore space and macrocapillaries (from 23.91% to 6.61%), water absorption (3 times), and the index of mean size of open capillary pores (from 0.69 to 0.3) of modified mortars.

PL

Odpowiednio niska przepuszczalność betonu to jeden z głównych czynników zapewniających trwałość i niezawodność konstrukcji budowlanych – mostów, tuneli, przepustów itd. Istotne jest zidentyfikowanie skutecznych metod zabezpieczenia takich konstrukcji przed wnikaniem wody, na przykład za pomocą dodatków modyfikujących. Badania nasiąkliwości przeprowadzono na próbkach zaprawy cementowej zawierającej dodatek emulsji asfaltowej. Na podstawie kinetyki wnikania wody w próbki oszacowano następujące parametry uzyskanej mikrostruktury porów: wskaźnik średniej wielkości otwartych porów kapilarnych, porowatość zamkniętą oraz wskaźnik jednorodności wielkości otwartych porów kapilarnych. Wyniki wykazały, że dodatek emulsji asfaltowej zmniejszył objętość porów i makrokapilar (z 23,91% do 6,61%), nasiąkliwość (trzykrotnie) oraz wskaźnik średniej wielkości kapilar otwartych (z 0,69 do 0,3) zapraw poddanych modyfikacji dodatkiem.

2

Quick-traffic slurry surfacing mix with orthophosphoric acid

Sidun Iurii, Vollis Oleksiy, Hidei Volodymyr, Bidos Volodymyr

Production Engineering Archives

|

2021

|

Vol. 27, Iss. 3

191--195

EN

Bitumen emulsions for slurry surfacing mix technology using oxidized bitumen and hydrochloric and orthophosphoric acids on laboratory DenimoTech bitumen-emulsion plant are made in the work. Methylene blue adsorption index of granite aggregate for use in slurry surfacing mix was investigated. Comparatively mix time and cohesion strength build-up of selected compositions slurry surfacing mix with hydrochloric and orthophosphoric acids depending on the variable content of bitumen emulsion. The advantage of using orthophosphoric acid in slurry surfacing mix according to the cohesion strength build-up criterion has been proved. The importance of correct distribution of bitumen drops in the emulsion was confirmed using a sedimentograph Mastersizer 2000. Two emulsions of the same component composition were compared, which differed in particle size. It has been established that it is not possible to design a slurry surfacing mix using the mix time criterion with the help of coarse bitumen emulsion.

3

Fatigue life comparison of recycled cold mixes with different type of bitumen binder

Buczyński P.

Structure and Environment

|

2016

|

Vol. 8, no. 4

217--223

EN

Knowledge of the fatigue life is required to properly predict pavement structure reliability with respect to the number of loading cycles. The possibility of using foamed bitumen and bitumen emulsion as binders in the composition of road bases makes it necessary to identify the influence of the binder type on the service life of these layers through dynamic tests. Obtaining proper physical and mechanical parameters does not necessarily ensure the correct evaluation of the recycled base quality. Satisfaction of the quality-related requirements does not guarantee the provision of the required fatigue life parameters. Cold recycled bases with cement should work within the viscoelastic range due to hydraulic bonding in the structure. If this range is exceeded, a considerable rise in strains occurs as a result of brittle fracture, leading to the loss of fatigue life. The paper presents the results from the fatigue tests of recycled bases. The amount of bitumen used in both cases was 3% and 5%. For the production of the bitumen emulsion and foamed bitumen, 70/100 pen bitumen was used. Portland cement I 32,5R was applied as a binder. The binder comprised 3% of the mineral composition of the recycled base layer. Fatigue tests were performed in compliance with the requirements of enclosure E of PN-EN 12697-24 at a constant normal stress of 250 kPa, 375 kPa and 500 kPa. The results were used to compare the effects of the binder type applied to the recycled base and determine the service life in terms of the stress applied.

4

Evaluation of the pavement performance

Iwański M., Chomicz-Kowalska A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2015

|

Vol. 63, nr 1

97--105

EN

This paper focuses on evaluation of two laboratory-based methods of compaction of foamed bitumen and bitumen emulsion mixes: impact compaction with a Marshall hammer and static compaction using a hydraulic press. The investigated compaction methods were assessed in terms of their impact on the physical and mechanical properties of produced laboratory specimens, including: air void content, indirect tensile strength before and after conditioning in water (ITSdry, ITSwet), tensile strength ratio (TSR), and indirect tensile stiffness modulus (ITSM) at 0°C, 10°C and 20°C. The statically compacted specimens attained higher levels of mechanical properties and resistance to moisture damage, which was associated with a lower content of air voids in the specimens formed using a hydraulic press. Authors present a calculation showing that a mechanistic design based on the laboratory static press compaction method leads to overestimation of fatigue cracking resistance of the road base.