Sulfuric concrete

Sulfur concrete Sulfur copolymers Sulfur cures Sulfur cure system Sulfur dichloride... 

Sulfur concretes are used in many specialty areas where Porfland cement concretes are not completely satisfactory. Because SC can be formulated to resist deterioration and failure from mineral acid and salt solutions, it is used for constmction of tanks, electrolytic cells, thickeners, industrial flooring, pipe, and others. In addition, SC is under investigation for many other prospective uses (58,59) (see Cement). 

Sulfur concrete (SC), 23 592 Sulfur-containing compounds, in natural gas, 12 369... 

The Texas Transportation Institute has just completed a very extensive two year FHWA sponsored program to look into other aspects of safety and environmental impact of sulfur-asphalt construction [53]. A number of typical sulfur-asphalt and sulfur-concrete paving systems were evaluated to assess their potential environmental impact and establish safety considerations relative to their formulation, construction and maintenance. The environmental impact was investigated from the formulation stages, through weathering, and included considerations of simulated fires and chemical spills. 

Asarco tested components of sulfur concrete, both precast and poured in place, in corrosive environments of sulfuric acid. Favorable endurance of these samples led to a full-scale cooperative demonstration project. The project selected was the rehabilitation of an electrolytic zinc cellhouse basement floor of approximately 21,000 square feet. 

After 1- years, the Portland cement concrete control samples at Corpus Christi that were installed contiguous to and intermixed with the sulfur concrete test samples showed total disintegration, whereas the sulfur concrete exhibited no identifiable attack (figure 2). In the summer of 1979, the ongoing maintenance needs at the Corpus Christi plant placed rehabilitation of a cellhouse basement floor in a priority position. The opportunity to perform the repair work on a full-scale basis, utilizing Bureau of Mines technology for sulfur concrete in lieu of portland cement concrete, was accomplished by an agreement for a demonstration project executed between the Bureau of Mines and Asarco. 

Figure 1. Sulfur concrete sump for installation in the zinc electrolyte pumping circuit.

Figure 2. Sulfur concrete and control port land cement concrete (4-test sections each)in the floor area of the electrolytic zinc refinery. After 28 months, no corrosive attack is seen on the sulfur concrete sections, although the control samples were severely attacked.

Transport of the mixed sulfur concrete was accomplished by motorized wheelbarrows with insulated buckets (figure 5). Covers would have assisted in retaining the heat of the mix, but were not necessary in the summer months in south Texas. 

Figure 5. Transporting and pouring the hot sulfur concrete with an insulated motorized concrete buggy.

Sulfur concrete freezes like a metal casting. The surface forms a skin first. Once the skin is formed, no further work can be accomplished. It can be reheated within limits by radiant heat and further worked. A single-sweep method is most effective. 

The physical panel size used resulted in more joints between panels than would have been the case in a Portland cement pour, owing to the surface finishing with a screed and the continuous obstruction of the existing support columns. Asphalt expansion strips were placed between panels and were provided with a removable top strip which was filled with a polyurethane compound. Shrinkage of pours in this work was negligible. Shrinkage in sulfur concrete was proportional to the amount of sulfur binder used. 

Potentially every parameter of cost involved in sulfur concrete is a variable. The cost of sulfur and the cost to modify it, the availability and capacity of mixing equipment and the daily volume of material mixed, and the labor requirement at the mixing installation are variable factors for a specific project. Added to these variables are the normal parameters of a concrete jobsite preparation, form construction and grade delineation, transport, placement, finish, joint practice, and other items constituting the total concrete installation. Finally, a cost comparison must be made versus the local cost of Portland cement concrete, which is highly variable in different locations. 

Based on this experience and applied to a spread of ready-mix concrete cost of 40 to 80 a yard and extended to a range of quantity of sulfur concrete mixed per day, there is an indicated cubic yard comparison, materials only, of approximately 1% to 6 times the cost of Portland cement concrete for sulfur concrete. Greater volumes per day yield lower unit costs. Experience at Corpus Christi would put the premium cost of sulfur concrete approximately 15 pet more than the cost of Portland cement concrete. 

The experience of Asarco was limited to exposures in different concentrations of sulfuric acid. Researchers studying sulfur concrete indicate that it is resistant to many organic and inorganic compounds, but not to aromatics, strong caustic... 

At the conclusion of the paving work at Corpus Christi, two electrolytic cells were cast of sulfur concrete for use in the zinc refinery. Subsequent to the work at Corpus Christi, a sulfur concrete floor was applied in the nickel plant at the Asarco Amarillo copper refinery. An isolating barrier of bitu-mastic material was mopped on the concrete before the sulfur concrete pour. This floor, a substantially smaller area, was overlaid on a damaged existing floor. Similar techniques to those described were used in mixing and placement. 

Sulfur Concretes (1 , IS). A range of different approaches are emerging to fabricate numerous products from a mixture of elemental or modified sulfur and mineral aggregates. These include cast-in-place as well as preformed or precast items which were previously made from Portland cement. 

Sulfur concretes (SC) are basically simple materials, made by mixing sulfur plus certain additives with heated mineral aggregates. On cooling, SC sets to give a high-strength material with superb corrosion resistance. 

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