Impact of agricultural waste additive on 1-dimensional clay consolidation behaviour
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Innocent Mandla
- Date: 2014
- Subjects: Rice husk ash , Kaolinitic clay , Soil treatment , Soil consolidation , Soil stabilization , Agricultural waste , Landfills , Fills (Earthwork)
- Type: Article
- Identifier: http://ujcontent.uj.ac.za8080/10210/386034 , uj:5050 , http://hdl.handle.net/10210/13589
- Description: Soil treatment is of vital concern in geoenvironmental and construction engineering in present times as suitable naturally occurring materials are rapidly depleted. Efforts are continually invested towards the resourceful utilization of wastes as fillers, cement enhancers, stabilizers and blenders with little or no significant impacts on the environment. This paper explains the use of a locally available and abundant agricultural waste- Rice husk ash (RHA) in West Africa, Nigeria for the treatment and stabilization of kaolinitic clay (KC) sampled from an active landfill site in Johannesburg, South Africa. The impact of incorporating different percentages of RHA on the compressibility characteristics of a parent compressible landfill KC sample was investigated under a One-dimensional consolidation test. Compacted soil specimens were treated at optimum water content (OWC) and maximum dry unit weight (MDUW) by the addition of agricultural waste material to the parent KC. The compacted specimens were subjected incremental vertical loading in a fixed ring consolidometer device. This was done with a view to closely simulate the waste loading effects from a typical landfill on a treated and parent clay/clayey bottom barrier based on one-dimensional consolidation behaviours. The introduction of RHA waste material to the parent KC revealed an outcome with substantial improvements in compaction characteristics. Hence, the results presented herein showed the agricultural waste to positively increase one-dimensional rigidity while settlement was effectively decreased. From results and analysis, the KC stabilized with RHA can withstand loadings from waste heaps under conditions as were applied in this study. With due recommended examination by geoenvironmental specialists, the stabilized material may be considered as an environmental and cost saving beneficiation approach for use in landfill liners.
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Transformation and utilization of agricultural waste as component of green concrete for rural housing and development schemes
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Rice husk ash , Pozzolana , Strength of materials , Agricultural wastes - Recycling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217530 , uj:21651 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2016. Transformation and utilization of agricultural waste as component of green concrete for rural housing and development schemes.
- Description: Abstract: Several researchers have outlined cost saving and cement blending merits without compromising standards. As such, utilizing artificial pozzolana as supplementary cementitious materials (SCMs) in concrete engineering is well known. However, there is continual search for substitute materials. The use of Rice Husk Ash (RHA) as cementitious constituent in green concrete was studied. Its abundance paved way for the study to look into the compressive strength of the concrete type formed by partly substituting Ordinary Portland Cement (OPC) with RHA under short curing series. Analysis on RHA revealed significant properties of pozzolanic hardening. 60 cubes of 100 mm dimensions were cast with cement replacement by RHA ranging from 0-40% while adopting a 28 day targeted strength of 25 MPa as control. The cubes were cured at relative humidity (RH) of 95-100% and temperature (T) of 22-250C in a chamber for periods of 7, 14, 21 and 28 days. The outcomes displayed trends of strength gain, reduced density and compressive strength with increase in RHA. The 28 days density and strength of the normal concrete was 2465 kg/m3 and 28.57 MPa while the 10% RHA sample (i.e. best substitute matrix) had 2398 kg/m3 and 25.97 MPa respectively. The strength of 10% RHA/OPC concrete (25.97 MPa) was slightly higher than the adopted strength (25 MPa) at 28 days. This signifies its suitability as concrete constituents and can be a major cost reduction factor in rural shelter projects where less structural complexities are required. Hence, it can be employed in the construction of simple foundations and concrete composites.
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