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CONCRETE TECHNOLOGY32 CPI %u2013 Concrete Plant International %u2013 4 | 2025 www.cpi-worldwide.comAn advantage of mineral thermal insulation foams produced using the IAB process is that they can be manufactured directly on-site, potentially even using locally available materials. The key ecological benefit is the minimization of transportation distances and, consequently, the reduction in energy consumption. Instead of transporting pre-manufactured insulation materials, which contain a high volume proportion of air, only raw material components are transported and stored, which can lead to savings in logistics costs, and which is more space-efficient.Since the concrete product or precast concrete manufacturer can now take on the role of insulation manufacturer, it is necessary to allow for initial investment costs for machinery and plant technology. Furthermore, specific training of the technical personnel, especially the plant operators, is required.Legal regulations and approvalFor the use of alternative mineral thermal insulation materials, only national technical application standards apply, which vary from country to country [2]. Application standards for the use of mineral foams do not yet exist. The author of publication [3] provides an overview of the approval process and the current developments. For Germany in 2022, it is noted: \ far, two general building authority approvals have been granted for lightweight concrete blocks filled with mineral foam insulation.\Challenges and opportunitiesWhile the continuous production of mineral foam is unproblematic, special challenges arise during the filling process depending on the building material to be filled. Due to the capillary suction of the surrounding material (e.g., concrete, lightweight concrete), water can be drawn out of the freshly placed foam. This process, hereafter referred to as water migration, is essentially dependent on the porosity and the existing water saturation of the surrounding material, as well as the water retention capacity of the mineral foam. The consequence of water migration is that the fresh mineral foam \If a critical loss of water is reached, settlements, cracks, and ultimately the collapse of the entire pore structure occur.Research and development status at IABAt IAB, a production process for mineral foam has been developed that ensures its stability in highly absorbent environments. The negative impact of water migration on the quality of the mineral foam should not be minimized through pretreatment of the masonry units to be filled, but rather by accelerating the structure formation and increasing the water retention capacity of the foam.The process developed by IAB for producing a fast-setting mineral foam is based on mixing two mineral foams that are each based on different hydraulic binders. When these two binders react with each other, the setting and hardening behaviour is accelerated. By mixing both mineral foams, part of the water contained in the produced two-component foam is chemically bound within a few minutes, while at the same time a load-bearing structure is formed. As a result, the mineral foam remains stable despite ongoing water migration.Solidification behaviour of the mineral foamThroughout the manufacturing process, the mineral foam is present in three different states, which can be derived from the hydration of cementitious binders, as summarized in Table 2.Fig. 1: Water migration in a lightweight concrete block.Time after installation [min.] Binder system 1 Binder system 2 Binder system 3Water in the foam [wt.%]