Effect of Compactive Efforts on the Strength Properties of Groundnut Shell Ash Stabilized Reclaimed Asphalt Pavement

2013 ◽  
Vol 824 ◽  
pp. 12-20
Author(s):  
Joseph E. Edeh ◽  
Adrian O. Eberemu ◽  
James Mzuaor Aburabul

Large quantities of groundnut shell ash (GSA) are generated from the combustion of groundnut shell, disposed in large quantities on production sites while large volume of reclaimed asphalt pavements (RAP) aggregates are also generated during pavement rehabilitation and reconstruction and disposed along road alignments. This paper presents results of the laboratory evaluation of the effect of compactive efforts on the strength properties of GSA stabilized RAP with a view to determining its suitability as highway pavement material in pavement constructions. The RAP-GSA mixtures were subjected to Reduced British Standard light, RBSL (reduced Proctor); British Standard light, BSL (standard Proctor); West African Standard, WAS and British Standard heavy, BSH (modified Proctor) compactive efforts to determine the compaction characteristics, California bearing ratio (CBR), durability and water absorption characteristics. Test results show that the properties of RAP improved with GSA treatment. The particle grading improved from 99.13 % coarse aggregate and 0.87 % fines, with AASHTO classification of A-1-b for 100 % RAP, and 9.08 % coarse aggregate and 90.92 % fines, with AASHTO classification of A-4 for 100 % GSA to 15.6691.72 % coarse aggregate and 8.2884.32 % fines, with AASHTO classification in the range A-4 (silty soil) to A-1-a (granular materials), for the various RAP-GSA mixes. Maximum dry density (MDD) decreased while the optimum moisture content (OMC) increased with higher GSA content in the RAP + GSA mixes and with decreased compactive effort from BSH to RBSL. Optimum CBR values of 35.1% (unsoaked) and 44.1% (soaked) recorded for 90% RAP + 10% GSA mix achieved with BSH compactive effort, satisfied the durability requirements with insignificant expansion and water absorption and can be used as subbase material in flexible pavements construction. This research provides the results of evaluation of the effect of compactive efforts on the strength properties of GSA stabilized RAP as highway construction material, as it is based on CBR determination. Further work may be encouraged to assess resilient modulus of this material under cyclic load.

2013 ◽  
Vol 824 ◽  
pp. 3-11 ◽  
Author(s):  
Joseph E. Edeh ◽  
Manasseh Joel ◽  
James Mzuaor Aburabul

Large volume of reclaimed asphalt pavements (RAP) aggregates are generated during pavement rehabilitation and reconstruction and disposed along road alignment while large quantities of groundnut shell ash (GSA) are generated from the combustion of groundnut shell and also disposed in large quantities on production sites. This paper presents results of the laboratory evaluation of the characteristics of GSA stabilized RAP with a view to determining its suitability for use as highway pavement material in flexible pavements construction. The RAP-GSA mixtures were subjected to British standard light (BSL) (standard Proctor) compactive effort to determine the compaction characteristics and California bearing ratio (CBR). Test results show that the properties of RAP improved with GSA treatment. The particle grading improved from 99.13% coarse aggregate and 0.87% fines, with AASHTO classification of A-1-b for 100% RAP and 9.08% coarse aggregate and 90.92% fines, with AASHTO classification of A-4 for 100% GSA to 15.6691.72% coarse aggregate and 8.2884.32% fines, with AASHTO classification in the range A-4 (silty soil) to A-1-a [granular material, for the various RAP-GSA mixes. Maximum dry density (MDD) decreased while the optimum moisture content (OMC) increased with higher GSA content in the RAP + GSA mixes. Optimum CBR values of 22.2% (unsoaked) and 18.3% (soaked) were recorded for 80% RAP + 20% GSA and 90% RAP + 10% GSA mixes, respectively. This optimum mixes satisfied durability requirement with insignificant water absorption and can be used as subgrade material in flexible pavements. This research provides the results to the evaluation of GSA stabilized RAP as highway construction material, as it is based on CBR determination. Further work may be encouraged to assess resilient modulus of this material under cyclic load.


2011 ◽  
Vol 367 ◽  
pp. 3-11 ◽  
Author(s):  
Joseph E. Edeh ◽  
Adrian O. Eberemu ◽  
Onah Agnes

This paper presents the results of the laboratory evaluation of the characteristics of lateritic soil stabilized reclaimed asphalt pavements (RAP), using 0 – 2% cement, subjected to British Standard Light (BSL) compactive effort to determine their index, compaction and california bearing ratio (CBR) results. The result of the laboratory tests show that the properties of RAP improved when stabilized with lateritic soil, using up to 2% cement. The particle size distribution improved from poorly graded sandy GRAVELLY material for 100% lateritic soil and very sandy GRAVELLY material, to the gradation described as well graded very sandy GRAVELLY material for lateritic soil stabilized RAP, using up to 2% cement. The CBR results obtained from the study show that using the Nigerian General Specifications, 180% CBR value criterion, the maximum CBR of 55% (soaked) for the mix proportion; 40% Laterite + 58% RAP + 2% Cement for A-2-7(2) soil prescribed by the latter is not adequate for stabilization of base coarse. However, judging by the 24-hour strength gain from 17.9 (unsoaked) to 55% (soaked) CBR values, the material can be used as subgrade and subbase materials.


Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.


2019 ◽  
Vol 1 (6) ◽  
pp. 235-239
Author(s):  
Sabarinathan K ◽  
Ashwathi R

The growing environmental awareness and Construction waste, is increasing day by day which in turn makes the world in seeking for examining the characteristics of Construction waste and obtaining a solution by using its reliable segments such that it can be used as a raw material and Conservation the natural recourses like Coarse aggregate


Author(s):  
I.O. Mikulionok

The possibility of use of the heat-exchangers in whole or in part manufactured with use of polymers and plastics is considered. Despite obvious, at first sight, inexpediency of use of polymeric materials in the heat-exchange equipment (low coefficient of heat conductivity, and also low, in comparison with metals, the strength properties of the majority of the most widespread polymers), «polymeric» heat-exchangers find application in various areas of the industry more and more surely. Classification of heat-exchange apparatuses which constructive elements are executed with use of polymeric materials is proposed. The following signs are the basis for classification: polymer type, a type of polymer meric material, type of the heat-exchange apparatus (a form of heat-exchange elements), reliance on polymeric materials in apparatuses, motion freedom of polymeric heat-exchange elements, level of assembly of a design, and also diameter of tubular elements. Critical analysis the most characteristic designs developed by domestic and foreign designers and inventors is carried out. Ref. 21, Fig. 13.


Author(s):  
Abdulmumin Adebisi ◽  
Tajudeen Mojisola ◽  
Umar Shehu ◽  
Muhammed Sani Adam ◽  
Yusuf Abdulaziz

In-situ synthesis of high-density polyethylene (HDPE) reinforced groundnut shell particulate (GSP) composite with treated GSP within the range of 10-30 wt% at 10 wt% has been achieved. The adopted technique used in the production of the composite is melt mixing and compounding using two roll mills with a compression moulding machine. Properties such as hardness, tensile strength, impact energy and water absorption analysis were examined. The result revealed that addition of GSP increases the hardness value from 22.3 to 87 Hv. However, the tensile strength progressively decreased as the GSP increases in the HDPE. This trend arises due to the interaction between neighbouring reinforced particulate which appears to influence the matrix flow, thereby inducing embrittlement of the polymer matrix. It was also observed that water absorption rate steadily increased with an increase in the exposure time and the absorbed amount of water increases by increasing the wt% of the GSP. Analysing the obtained results, it was concluded that there were improvements in the hardness, tensile strength, impact energy and water absorption properties of the HDPE-GSP polymer composite when compared to unreinforced HDPE. On these premises, GSP was found as a promising reinforcement which can positively influence the HDPE properties of modern composites.


2001 ◽  
Vol 7 (6) ◽  
pp. 446-452
Author(s):  
Gintautas Skripkiūnas ◽  
Vitoldas Vaitkevičius

The results of experiments dealing with coarse aggregate concentration influence on the concrete strength and the structure of hardened cement paste and mortar of concrete are presented in the paper. Experiments were performed on concrete with dense coarse aggregate (crushed granite) which strength is more than strength of mortar and lightweight porous aggregate (expanded clay aggregate) with strength less than that of mortar. Physical and mechanical properties of concrete with dense coarse aggregate are presented in Table 1 and the concretes with the porous coarse aggregate in Table 2. The decrease of entrained air content with the increase of coarse aggregate concentration ϕσt were determined both for concretes with dense and porous coarse aggregate. The entrained air has a significant effect on concrete strength—1% of entrained air decreases the strength of concrete about 5% [11]. The influence of the coarse aggregate concentration on the compressive strength of concrete with the constant air content is presented in Figs 3 and 4. With the increase of coarse aggregate concentration the concrete strength decreases when the entrained air content in concrete is constant. The main reasons of the concrete strength reduction are the stress concentration and structural defects near the coarse aggregate. Coarse aggregate affects the structure of mortar. Dense coarse aggregate has negligible water absorption and does not change water content in mortar of concrete, and capillary porosity of mortar remains constant when the concentration of dense coarse aggregate ϕ st increases (Fig 5). Porous coarse aggregate (expanded clay aggregate) has large water absorption (more than 16%), therefore water content in mortar of concrete is reduced and capillary porosity of mortar is significantly reduced when the concentration of porous coarse aggregate ϕ st increases (Fig 5). The entrained air content in mortar with both dense and porous coarse aggregate decreases inverse proportionally to coarse aggregate concentration ϕ st (Fig 6). The investigations have shown that suitable selection of properties and volumetric concentration of coarse aggregate can reduce stress concentration in concrete and increase the concrete strength.


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