Agricultural wastes and sawdust combined with cement matrix in the manufacture of building elements has been practiced with success in developed countries. In this study, sawdust from wood species (Pinus caribaea and ...Agricultural wastes and sawdust combined with cement matrix in the manufacture of building elements has been practiced with success in developed countries. In this study, sawdust from wood species (Pinus caribaea and Eucalyptus grandis) and an agricultural waste—rice husk (Oriza sativa) were combined with Portland cement type V (high initial strength), modified by polymer styrene-butadiene (SBR) addition. Hollow blocks produced with Eucalyptus grandis and rice husk residues showed better compressive strength;however, those produced with residues derived from Pinus caribaea presented non-satisfactory results, due to the particle size that was used.展开更多
Agro-industrial activities generate a large amount of wastes. According to their specific properties, most of them can partially replace mineral aggregates, aiming to produce non-structural cement composites. In this ...Agro-industrial activities generate a large amount of wastes. According to their specific properties, most of them can partially replace mineral aggregates, aiming to produce non-structural cement composites. In this research work, the behavior of a Portland cement mortar with partial replacement of sand by treated eggshell particles (0% to 66%) has been evaluated. Firstly, chemical compatibility between eggshell particles and Portland cement was carried by hydration curves. In a second step, a mixture of cement mortar based on treated eggshell (cold water, warm water and oven-dry) was prepared. Composite hardening was monitored by an ultrasound technique. At initial ages, ultrasonic pulse velocity (UPV) along the time was sensitivity enough to detect the sand-to-eggshell ratio effect. Compressive strength at 28 days ranged from 23 to 9 MPa depending on sand to eggshell particles ratio, which indicated that the composite was suitable for non-bearing structures, mainly at rural areas.展开更多
文摘Agricultural wastes and sawdust combined with cement matrix in the manufacture of building elements has been practiced with success in developed countries. In this study, sawdust from wood species (Pinus caribaea and Eucalyptus grandis) and an agricultural waste—rice husk (Oriza sativa) were combined with Portland cement type V (high initial strength), modified by polymer styrene-butadiene (SBR) addition. Hollow blocks produced with Eucalyptus grandis and rice husk residues showed better compressive strength;however, those produced with residues derived from Pinus caribaea presented non-satisfactory results, due to the particle size that was used.
文摘Agro-industrial activities generate a large amount of wastes. According to their specific properties, most of them can partially replace mineral aggregates, aiming to produce non-structural cement composites. In this research work, the behavior of a Portland cement mortar with partial replacement of sand by treated eggshell particles (0% to 66%) has been evaluated. Firstly, chemical compatibility between eggshell particles and Portland cement was carried by hydration curves. In a second step, a mixture of cement mortar based on treated eggshell (cold water, warm water and oven-dry) was prepared. Composite hardening was monitored by an ultrasound technique. At initial ages, ultrasonic pulse velocity (UPV) along the time was sensitivity enough to detect the sand-to-eggshell ratio effect. Compressive strength at 28 days ranged from 23 to 9 MPa depending on sand to eggshell particles ratio, which indicated that the composite was suitable for non-bearing structures, mainly at rural areas.
