Challenging Aggregates
Sika developed a concept for finding the right solution for the issues observed by the customer related to sands and aggregates. In many cases, the reason for changing or problematic concrete properties is not obvious. Therefore, several steps are required to identify the problem to give the right support and product solutions. With our Sika CODE method, we can address these challenges to find solutions.
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We want to help you unlock the safe using the Sika CODE method:
Solving Aggregrate Issues in Concrete Production with the Sika CODE
Four Steps in the Sika CODE
It is important to listen to the customer and understand the issues or challenges that he or she must solve. Sika experts discuss the problems with customers - namely concrete producers - while making sure to fully understand their needs.
The following issues may arise in concrete production:
The concrete requires more
water to be added for the same fresh concrete properties.
The concrete requires a higher admixture dosage.
The concrete shows higher adhesion and cohesion than before.
With the same water content, the concrete shows bleeding or even segregation.
The pumpability is reduced with the current concrete mix. This can lead to blockages during pumping or higher pumping pressure required.
Using low quality sands can lead to issues on the concrete surface, especially in precast concrete.
The workability time of the concrete is affected by the sands or aggregates used for the concrete mix design.
The next step in the Sika CODE concept is the analysis. Samples of the sands and aggregates are analyzed using several methods in the Sika technology lab.
The focus of the analysis involves the following points:
It is important to identify critical minerals within the sand which can negatively influence the concrete performance.
The correct grading curve is important for the concrete properties. This needs to be tested, and gaps need to be identified.
The aggregates and sands used in the mix can lead to absorption of water or admixtures. This depends on the mineralogy of the sands. With specially developed lab tests, this absorption behavior can be investigated.
The single particles of the sands and aggregates are analyzed regarding their shape and grain properties, which can have a high influence on the concrete behavior.
With the analytical results, the cause of the customer challenge can be diagnosed. Of course, it can be that there are several causes that lead to an issue.
However, most of them can be found in this list:
The sand or aggregates absorb water from the mix design.
The sands or aggregates absorb admixtures added to the concrete mix.
The particles have an unfavorable shape (e.g. too edgy for crushed sands).
The grading curve contains a high fine content.
The grading curve shows a lack of fine particles.
After the identification of the cause, our Sika experts can work on the most effective solution for our customer. The solution can be a product, combination of products, technical support or both products and support (as in most cases).
Amongst others, the following solutions can be offered:
A mobile phone application is an analytical device and provides information about aggregate particle size, shape, and distribution together with fineness modulus.
Sika technical expertise is offered for every customer to support on site with our expert knowhow and products and in the lab with testing and analysis.
This includes the whole range of Sika water reducers - for example Sikament®, SikaPlast® or Sika® ViscoCrete® technology.
The Sika® Stabilizer range helps to optimize concrete properties and provides robust solutions for fluctuating sand qualities.
Solving Aggregrate Issues in Concrete Production with the Sika CODE
The Sika Sand App is a step toward optimized identification of available aggregate and towards finding alternatives to overcome shortage of high-quality aggregate without significant performance loss.
Sika Sand App is another solution included in the full range of assistance offered to our Sika TM Concrete customers in the USA. To learn more about the solutions we have to offer, please contact a Sika sales representative in your region.
