Suitability Assessment of Construction and Demolition Waste as a Highway Material

For Being a developing country urbanization is growing rapidly in Bangladesh and there has been a significant increase in the construction of roads. But due to lack of financial aid many of the roads are still unsealed. However, not only the utilization of Construction and Demolition Waste (CDW) in flexible pavement will be helpful for the reduction of road construction costs but also it will help to reduce environmental pollution which may be caused by disposing CDW in open area. The objective of this research is to utilize the CDW in base and sub base layers in the flexible pavement design to reduce the cost of road construction and environmental pollution. Proceeding by collecting CDW like brick from demolished building and conventional brick from kiln, a no of standard test conducted in laboratory namely Aggregate Impact Value, Crushing Value, Specific Gravity, Water Absorption and Loss Angeles Abrasion Test for three times. After analyzing the test results, we found that the average Aggregate Impact Value for CDW and Conventional Aggregate (CA) are respectively 29.52% and 23.87%, Aggregate Crushing value for CDW and CA are respectively 28.10% and 22.88%, Los Angeles Abrasion value for CDW and CA are respectively 31.47% and 28.52%, specific gravity value for CDW and CA both is 1.75, water absorption for CDW and CA are respectively 7.62% and 12.23%. After analyzing the test results and comparing with the standard value, we figure out that the CDW are useful for using base and sub base layers in the flexible pavement.

Effects of Concrete Grades on Strength Characteristics of Metakaolin Modified Recycled Aggregate Concrete

In this study, locally produced Metakaolin (MK) was used as an admixture in recycled aggregate concrete of grades M 25 and M 30. The content of MK varied from 0-15% at 5% intervals. The physical and mechanical properties (bulk density, specific gravity, water absorption, aggregate crushing value and aggregate impact value) of aggregates were determined, the chemical composition as well as reactivity of MK was evaluated using X-Ray Fluorescence (XRF) technique and modified Chappelle test. The workability (slump) and strength (compressive and split tensile) properties of fresh and hardened RAC were examined relative to that of conventional concrete. The results of the experiments revealed that the specific gravity (SG), water absorption and aggregate impact value of recycled aggregates (RA) were 2.23, 5.35% and 32%, respectively. The MK used had an optimum reactivity of 2060.8 mg of Ca(OH)2 fixed at a temperature of 660 oC. The slump values for M 25 and M 30 control specimens were 72 mm and 65 mm, respectively while the slump values of MK modified RAC decreased from 67-45 mm for M 25 and 55-35 mm for M 30 as MK increased from 0-15%. The 56th-day compressive strength of the control samples was 21.73 N/mm2 for M 25 and 26.8 N/mm2 for M 30, respectively, while RAC samples ranged from 14.96 - 17.04 N/mm2 for M 25 and 20.55 - 22.67 N/mm2 for M 30 whereas the split tensile strength for the control samples was 2.71 N/mm2 and 3.06 N/mm2 for the two grades in that sequence, while those of RAC ranged from 2.26-2.49 N/mm2 for M 25 and 2.62 – 2.84 N/mm2 for M 30. Despite the fact that metakaolin modified RAC had lower strength properties than conventional concrete, the use of 10% metakaolin as a RA modifier in concrete production will provide a sustainable alternative to conventional aggregates in concrete mix design.

Effects of Granite Sourced from Selected Locations in Ogbomoso, Nigeria on the Properties of Concrete

Aggregates constitute 60 – 80% of total concrete constituents. The characteristics of concrete may be affected by the sources from which the aggregate was obtained. The effects of granite sourced from four selected locations within Ogbomoso, Nigeria; on the fresh and hardened properties of concrete were investigated. The granites were obtained from: Asafa (80 4.681 N and 40 20.781 E), Ola-jesu (80 13.591 N and 40 10.11 E), Igbo-ile (80 4.681 N and 40 19.571 E) and Apasu (80 14.961 N and 40 10.051 E). Sieve analysis, specific gravity, moisture content, Aggregate Crushing Value (ACV) and Aggregate Impact Value (AIV) of the granites were determined. The aggregates were used to produce concrete of two different mix ratio-1:2:4 and 1:3:6. Slump and compaction factor tests were carried out on fresh concrete and compressive strength, splitting tensile strength and water absorption on hardened concrete. The results indicated that granite obtained from Asafa and Ola-jesu exhibited improved characteristics over those sourced from Igbo-ile and Apasu and are more suitable for use in producing high-quality concrete.

Performance of Porous Asphalt Mixture Containing Seashell as Aggregate Replacement

Porous asphalt pavement is mainly used for parking lots which able to let water to drain through the pavement surface into a stone recharge bed and infiltrate into soils under the pavement. This study is to investigate the performance of seashell in porous asphalt and determine the image analysis. The seashell used in this study is cockle shell. The strength of seashell was determined through the Aggregate Impact Value Test (AIV) and Aggregate Crushing Value Test (ACV). The grade of bitumen used was grade 60/70. The porous asphalt volumetric properties was determined through Marshall Stablity Test. The permeability coefficient of sample that contain seashell as aggregate replacement was determined through Permeability Test. Generally, the results shows that the seashell’s percentage loss (AIV and ACV) is suitable use for porous asphalt mixture, where the percentage of loss for AIV and ACV was 27.84% and 7.65% respectively. Based on the Marshall Test, porous asphalt that containing seashell as aggregate replacement shows a different result, where it had lower stability value and it can increase the bulk density of porous asphalt mixture. Furthermore, the permeability coefficient also increase. The surface of seashell able to bond with bitumen. Lastly, the trend of VFA and VTM value is effected by the surface and position of seashell in the porous asphalt sample.

Rutting Performance of Road Using Construction and Demolition Waste Materials

Wastes arising from construction and demolition (C & D) constitute one of the major streams in many countries. In this paper experimental investigation was carried to see the feasibility of C& D waste as road aggregates. From the grading analysis it was observed that using C& D wastes, strength criteria is being satisfied and meet the specifications of MORTH which is then subjected to aggregate impact value (AIV) testing, CBR testing etc. The CBR value of C&D waste was found to be 43.46 which were well above the permissible value. A proposed three-layer system using soil layer, C & D waste layer and asphalt concrete layer is chosen to estimate rut depth using existing analytical model. From the analytical model rut depth is predicted to be 14.77 mm which is less then maximum allowable limits. Hence C& D waste materials can be used as alternate materials in road construction with economy and sustainability.

The Effects of Various Concentrations of NaOH on the Inter-Particle Gelation of a Fly Ash Geopolymer Aggregate

Aggregates can be categorized into natural and artificial aggregates. Preserving natural resources is crucial to ensuring the constant supply of natural aggregates. In order to preserve these natural resources, the production of artificial aggregates is beginning to gain the attention of researchers worldwide. One of the methods involves using geopolymer technology. On this basis, this current research focuses on the inter-particle effect on the properties of fly ash geopolymer aggregates with different molarities of sodium hydroxide (NaOH). The effects of synthesis parameters (6, 8, 10, 12, and 14 M) on the mechanical and microstructural properties of the fly ash geopolymer aggregate were studied. The fly ash geopolymer aggregate was palletized manually by using a hand to form a sphere-shaped aggregate where the ratio of NaOH/Na2SiO3 used was constant at 2.5. The results indicated that the NaOH molarity has a significant effect on the impact strength of a fly ash geopolymer aggregate. The highest aggregate impact value (AIV) was obtained for samples with 6 M NaOH molarity (26.95%), indicating the lowest strength among other molarities studied and the lowest density of 2150 kg/m3. The low concentration of sodium hydroxide in the alkali activator solution resulted in the dissolution of fly ash being limited; thus, the inter-particle volume cannot be fully filled by the precipitated gels.

Characterization of Classified Indian Reclaimed Asphalt Pavement (RAP): Aggregate Impact Value and Aggregate Abrasion Value of Rap Aggregates

Reuse of existing deteriorated bituminous pavement material in construction and maintenance of flexible pavement is called recycling of bituminous pavement. Removed and reprocessed deteriorated pavement material which is recycled is termed as Reclaimed asphalt pavement (RAP). In India during construction of flexible pavement different types of bituminous layers are in practice depending upon CBR of sub-grade and traffic count i.e. CVPD of the road stretch. Depending upon types of bituminous layer i.e. PC Seal Coat, Bituminous Macadam(BM), Dense grade bituminous Macadam (DBM), Semi Dense Bituminous Concrete (SDBC) or Bituminous Concrete(BC) Reclaimed Asphalt Pavement can classified in different groups These classified RAP groups materials will have different characteristics i.e. Rap aggregates and Recovered bitumen of different group of RAP will have different characteristics. In this study characterization of RAP limited to Aggregate Impact Value (AIV) and Aggregate Abrasion Value (AAV)of RAP aggregates of RAP classified in different groups. Results of this study will be compared to standard value of AIV and AAV required for bituminous construction to predict that RAP aggregates are suitable or not for use in bituminous mixes.

Assessment of Rock Aggregate for Construction Using Comminution Theory

In this research, grinding energy of selected rock samples collected from South West Nigeria was determined using comminution theory in order to evaluate suitability of rock for aggregate production. Bond Work Index (BWi), Aggregate Impact Value (AIV) and Aggregate Crushing Value (ACV) of samples was characterized and correlated. The work index of the charnockitic rock, granite gneiss, porphyritic granite –labelled PG1 and porphyritic granite –labelled PG2 of samples was found to be 17.12 kWh/t, 13.72 kWh/t, 13.64 kWh/t and 12.76 kWh/t respectively. The ACV of the charnockitic rock, granite gneiss, porphyritic granite (PG1) and porphyritic granite (PG2) was determined to be 26.2 %, 27.3 %, 27.6 % and 27.8 % respectively; while the AIV of the samples, in same order, was 11.2 %, 13.2 %, 19.1 % and 18.4 % respectively. Following high correlation coefficient of 0.98% between BWi and ACV, hardness of rock materials are classified as ‘very difficult’, ‘difficult’, ‘medium’, ‘easy’ and ‘very easy’ for grinding energies in the range of >18 kWh/t, 14-18 kWh/t, 10-14 kWh/t, 7-10 kWh/t and 0-7 kWh/t respectively. Based on the classification, rock materials with grinding energy >10 kWh/t could be suitable for aggregate production and usable for civil construction purposes.Keywords- Aggregate, Aggregate impact value, Aggregate crushing value, Comminution, Grinding energy.

Design of Normal Concrete Mix Based on Both Building Research Establishment and American Concrete Institute Method of Mix Design

To achieve a defined workability, strength and durability in construction works, concrete mixes are designed and this is done towards the selection and proportioning of constituents to produce a concrete with pre-defined characteristics both in fresh and hardened states. This study assesses the design of normal concrete mix based on the American Concrete Institute and Department Of Environment methods of mix. A characteristic strength of 20 N/mm2 was designed for using the two mix design methods. The concrete components used were tested for specific gravity; moisture content, particle size distribution, aggregate impact value, aggregate crushing value, slump test and compacting factor test and were found suitable. Two sets of concrete cubes (150 x 150 x 150 mm) each were cast using two mix designs. Compressive strengths were evaluated at 7, 14, 21, and 28 days of curing. The 28th day strengths of the two sets of concrete were found to be 30.5 N/mm2 and 29.5 N/mm2 for both DOE and ACI mix design methods which did not exceed the calculated targeted strength.