the thesis of Ignacio Kröger Engineers and Carlos Pfeiff on the performance of highly modified asphalts (HiMA) was recently introduced.
Last July 4th fought against the Ing. Magdalena Pastorini, Ing. Arturo Forteza and Lic. Laura Luzuriaga with the final thesis which took more than eight months of intense work on a comparative study between the Hima the AM3 and AC30.
Continue read: REGIONAL MEETING IN BOLIVIA CIVIL ENGINEERING
In this thesis several technical papers to be presented at the 12th Congress of the Road Uruguaya and in the XX IBWC to be held in November in Mexico are released. Moreover it is performing a scaling himâ asphalt plant are preparing the experimental sections to assess their field performance in the long term.
Using the penetrometer ball as quality control element base treatment.
In the path that is being traced at the national level to standardize design criteria for surface treatments, we believe the inclusion of the ball penetrometer test is of utmost importance. It determines if the base is in proper condition to receive initial treatment, or if it requires additional work. It is also an indicator of the degree of compaction that has been achieved and the moisture contained in the base. The test was originally developed by South Africans and is also used in Australia and New Zealand to quantitatively measure the penetration potential of aggregate into the base.
En este frío mes de Agosto, junto con Lucio Borelli de CVC, pusimos a prueba este equipo de medición en diversas superficies: bases granulares no ligadas, bases estabilizadas con ligantes (cemento Portland y asfalto espumado) y mezclas asfálticas. A continuación se ilustran algunas de las conclusiones, acompañadas de fotos de la experiencia.
In the initial treatments (surface treatments on bases), the subsidence of the aggregate on the surface always occurs, to a greater or lesser extent. The degree of penetration will depend on the base material, its humidity, compaction and the traffic to which it will be subjected. Not taking these parameters into account results in exudate in the short term, becoming particularly evident in the tracks. The explanation for this phenomenon is intuitive: the tire pressure sinks the stone into a base that allows it and the voids that correspond to the asphalt and the air (to achieve the macrotexture of the wearing course) are occupied by the material of base, causing the asphalt to surface through the stone, which results in exudation in the tracks.
El ensayo que se propone es muy sencillo y de fácil aplicación: consiste en la penetración de una bola de 19 mm de diámetro que es golpeada por un martillo normalizado lanzado de una altura conocida (Australian Standards: AG-PT/T251 – Ball Penetration Test). El valor de penetración queda registrado en el aparato, ya sea en un indicador electrónico o en una regla graduada (que viene incorporada).
Los resultados de este ensayo se utilizan para ajustar la cantidad de ligante a regar o para seleccionar un tratamiento correctivo previo al definitivo. Su uso más importante es quizá el de establecer el límite en el que no se pueden realizar gravillados sin antes recompactar o estabilizar la base, dado que su riesgo de falla es muy elevado.
La primera y más importante de las conclusiones es que la preparación de la base es un factor determinante en los resultados. Un problema común es que las bases presentan un exceso de finos en la parte superior que genera que la bola penetre con facilidad. Aunque parecen estar lisas y homogéneas inicialmente, tan pronto como se barren, una gran cantidad de este material fino se dispersa, dejando una superficie áspera e inconsistente que es problemática para ejecutar un tratamiento.
Another issue to consider is the humidity at the time of the test: if the surface is visibly wet, the penetration gives higher values. We could corroborate this by testing the same surface early in the morning and close to noon. In some cases, the conditions of the base at the time of the test are good, but when a primer is applied, due to capillarity and temperature differences, humidity begins to increase in the first 5 cm, affecting the penetration result.
Developing
New Reómetro Anton Paar SmartPave 102 at sion It will allow a big step in the performance of asphalt products in Uruguay.
As we announced in an earlier issue of our newsletterThis month installed a Court Dynamic Rheometer (DSR for its acronym in Ingés). This sophisticated equipment allows to know the performance of asphalts much of its viscoelastic range. Mainly we are concerned in these latitudes, that is at medium and high temperatures.
With this tool we can improve the modified asphalts and emulsions to suit the conditions of our country and know within minutes the quality of asphalts used as raw material.
With the addition of equipment, a course of rheology and use of equipment with an expert from the supplier was performed. The course was held on 27 and 28 August in the CITEVI and we have the participation of technical staff of our company, the MTOP and LATU.
This new machine is equipped with accessories for measurements from -20 to 150 ° C both conventional asphalts, as well as some modified properties of emulsions. Typically it used to determine the degree of asphalt (PG) but can be used for other properties of the binders.
Within the novel assays we can discuss the possibility of making master curves where temperatures and voltages applied to see the performance of the binders are varied. It is also possible to test highly accurate adhesion or cohesion at different temperatures, essential for the performance of emulsions for surface treatment tool.
Not so new but convenient is the possibility of viscosities "brookfield" within minutes both 60 ° C to the viscosity curves at the desired temperature range.
These are some of the many tests that can be performed but the team is extremely versatile and has many accessories that allow analyzing from food to paint smoothly.
In the course they made the basics of fluid mechanics, equipment operation and its application to the asphalts were given. It had a practical module to understand the operation of equipment and advanced software that controls and processes data.
Much remains to explore and contribute to our road with this team. We will keep you informed of progress.
We have a new online platform to access the quality reports of our products.
It is accessed from the website of GRUPO BITAFAL section Practice Areas / CITEVI / Lab Reports and there is also a direct access from the home page of the web.
There are monthly folders of all products coded by the corresponding batch number. A modification has been made in the delivery notes delivered with each load and the batch number of each is indicated next to the product.
To access the platform it is necessary to have a password that has been sent by email to our clients. In case you have not received this email, we request that you write to us at bitafal@bitafal.com.uy
We hope it will be useful to you and were open to suggestions to further improve communication.
