Cement - steatite composites reinforced with carbon fibres: an alternative for restoration of brazilian historical buildings

Abstract

Steatite is a mineral which has been employed in the carving of elements in facades of Brazilian historical buildings and churches since the 17 th century. Over the years, many of those historical buildings suffered the consequences of weathering with a current need for restoration. Recently a special cement-based mortar containing additions of fine powder waste from mineral extraction of steatite has been developed in Brazil, as a composite material for restoration of steatite elements. However, the incorporation of steatite waste reduces the flexural strength of the mortar and compromises the restoration of elements where gravity imposes tensile stresses. The addition of carbon fibres may overcome this issue and increase the flexural strength of the cement-steatite composite mortar. This work investigates the effect of carbon fibre addition on the bulk density and flexural strength of compacted precast cement-steatite composites. The results show that the addition of carbon fibres (i) effectively increases the mechanical strength, allowing for a higher amount of steatite powder waste in the mixes; (ii) reduces the weight of the structural elements. This new composite material would help to develop restoration techniques of historical buildings and serve as a disposal route of steatite powder waste in Brazil.

Statistical design of polymeric composites reinforced with banana fibres and silica microparticles

“…However, an opposite behaviour can be expected (and has been experimentally observed) for silica particles under compression loads, because of the beneficial effect on the interface adhesion between matrix and particulate phases under that specific loading. 28 …”

Influence of Ultrafine Natural Steatite Powder on Setting Time and Strength Development of Cement

“…It was observed that the highest compressive strength (43 MPa) and lowest apparent porosity (0.19%) are achieved when steatite particles are coarser (ranging from 1.41 mm to 0.42 mm), and 40% of polymeric phase is employed [5]. A special cementbased mortar containing additions of fine powder waste from mineral extraction of steatite has been developed in Brazil, as a composite material for restoration of steatite elements [6]. The steatite is mostly used in electrotechnics.…”

Experimental Investigation of Crystalline Silica in Concrete

“…The explanation of the difference is associated with various reasons, such as higher solid mass for those mixes and lower percentages of capillary pores. It is important to point out that the effect of Water and Cement ratio is almost impossible to understand at the early ages of concrete samples due to the higher amount of capillary pores (Panzera et al 2011).…”

“…Higher aggregate sizes and amounts increase the UPV measurements. Also, a decrement in the compressive strength occurs due to the high aggregate amounts (Panzera et al 2011). To get positive values from both tests, a high amount of attention should be paid during the mix design procedures.…”