Multimodal Discourse Analysis of 2012 Governorship Election Campaign Billboards in Ondo State, Nigeria

Billboards are widely used in the world for political purposes. The Ondo State 2012 governorship candidates employed billboards for their campaigns. It is observed that an average viewer of the campaign billboards finds it difficult to attain the exact interpretation of the semiotic devices in the pictures as intended by the producers. The objectives of this paper are: the analyses of the political discourse of the multimodal texts in the billboards and the exploration of the nature of the multimodal texts. This paper adopted the text dimension, the discursive practice dimension and the social practice dimensions of Fairclough’s (1992, 1995) three-dimensional framework. This theoretical framework was used to analyse and discuss the selected campaign billboards. The data collected for this study consisted of three governorship campaign billboards which were purposively selected. The study discovers that colours are meaning signifiers in the selected billboards and that the pictures, colours and verbal anchorages together with the various interpretations given them show the polysemic nature of signs. This paper concludes that visual resources are essential tools employed by campaign billboards’ producers. Finally, the study recommends that producers of campaign billboards should ensure simplicity and relevance of the semiotic resources used in the visuals. Keywords: Governorship elections, Campaign billboards, Multimodality, Verbal anchorages, Colours DOI: 10.7176/NMMC/95-04 Publication date: January 31st 202

Experimental Study on the Workability of Self-Compacting Granite and Unwashed Gravel Concrete

This study deals mainly with the mix proportions using granite and unwashed gravel as coarse aggregate for self-compacting concrete (SCC) and its workability, by considering the water absorption of unwashed gravel aggregate. Mix proportions for SCC were designed with constant cement and fine aggregate while coarse aggregates content of granite-unwashed gravel combination were varied in the proportion 100%, 90%/10%, 80%/20%, 70%/30%, 60%/40%, 50% /50%, represented by SCC1, SCC2, SCC3, SCC4, SCC5 and SCC6. 100% granite (SCC1) serves as the control. The workability of the samples was quantitatively evaluated by slump flow, T500, L-box, Vfunnel and sieve segregation tests. Based on the experimental results, a detailed analysis was conducted. It was found that granite and unwashed gravel with SCC1, SCC2 and SCC3 according to EFNARC (2002) standard have good deformability, fluidity and filling ability, which all passed consistency test. SCC1, SCC2 and SCC3 have good passing ability while all mixes were in the limit prescribed by EFNARC (2002). It can be concluded that the mix design for varying graniteunwashed gravel combination for SCC presented in this study satisfy various requirements for workability hence, this can be adopted for practical concrete structures

INFLUENCE OF GRANITE-GRAVEL COMBINATION ON THE STRENGTH OF SELF-COMPACTING CONCRETE: TOWARDS A SUSTAINABLE CONSTRUCTION MATERIAL

This study focusses on the influence of granite-gravel (washed and unwashed) combination as coarse aggregate on hardened properties of Self-Compacting Concrete (SCC). Granite-gravel combination in varying percentages was used as coarse aggregates to produce SCC while other concrete constituents were kept constant. The experiments executed on hardened SCC were compressive and split tensile strength. Concrete were made using 150 mm cubes and 100 mm × 200 mm cylinders. Data obtained were analysed using graphical illustrations while Minitab was used to model values for the mix proportions. The compressive strength of SCC produced reliable results with a minimum strength of 30.96 N/mm² for 50% washed gravel at 28 days of which, the strength also increases as curing age increased. The split tensile strength of SCC increases as the curing day increased but decreased as gravel content increased with 50/50 threshold limit. The Surface plots analysis shows that the percentage increase of granite-washed gravel combination as coarse aggregate and curing ages in SCC has significant impact on compressive strength. It can be concluded that granite/gravel combination as coarse aggregates in SCC production is feasible and reliable provided the threshold limits of 50% washed gravel and 30% unwashed gravel are not exceeded

EXPERIMENTAL STUDY ON THE DURABILITY TO SALINE ENVIRONMENTS OF SELF-COMPACTING CONCRETE MADE WITH COARSE AGGREGATES COMBINATION

This study focus on durability to saline environments of self-compacting concrete (SCC) made of granite-gravel combination as coarse aggregates in concrete production. In this study fine aggregates, water, superplasticizer and cement were kept constant. The percentages replacement of gravel in place of granite aggregates were 10, 20, 30, 40, and 50, while 100% granite serves as control. A total of 162 cubes of 100 100 100 mm concrete specimens were immersed over the initial curing in a water container and further cured in 5% sodium chloride (NaCl) and sodium carbonate (Na2CO3) solutions for 28, 56 and 91 days in line with ASTM C39 (2003). The tests results indicate that concrete cured in five percent (5%) of NaCl solution have compressive strength accelerating properties at early age that could not be sustained for long. While those cured in 5% of Na2CO3 solution reduced significantly the compressive strength of concret

Compressive Behaviour of Coconut Fibre (Cocos nucifera) Reinforced Concrete at Elevated Temperatures

Fire outbreaks in buildings have been a major concern in the world today. The integrity of concrete is usually questioned due to the fact that after these fire outbreaks the strength of the concrete is reduced considerably. Various methods have been adopted to improve the fire resistance property of concrete. This study focused on the use of coconut fibre to achieve this feat. In this study, varying percentages of treated and untreated coconut fibres were incorporated into concrete and the compressive strength was tested for both before heating and after heating. The percentages of replacement were 0.25, 0.5, 0.75 and 1% fibre content by weight of cement. Concrete cubes that had 0% fibre served as control specimens. After subjecting these concrete cubes to 250 �C and 150 �C for a period of 2 h, the compressive strength increased when compared to the control. The compressive strength increased up to 0.5% replacement by 3.88%. Beyond 0.5% fibre, the compressive strength reduced. Concrete having coconut fibre that had been treated with water also exhibited the highest compressive strength of 28.71 N/mm2. It is concluded that coconut fibres are a great material in improving the strength of concrete, even after it was exposed to a certain degree of elevated temperature

Production of Particleboard from Agricultural Waste - A Sustainable Approach to Waste Management

Large amounts of agricultural waste are left unutilized in Nigeria, resulting in detrimental environmental consequences. Particleboard made from such trash would help to reduce deforestation and have a good impact on the environment. The characteristics of particleboard made from corn cob (CC) and sugarcane bagasse (SB) with cassava starch and urea formaldehyde as separate binders were compared in this study. CC and SB mix proportions of 90:10, 70:30, and 50:50 percent (by volume) were used to make three layers of medium density particleboard. Manual mixing and blending of 25% and 10% by volume of the different binders and water respectively was done. The mixtures were compressed for 1 hour at 100 °C and 342 kg/m2. The ASTM D. 1037-12 (2020) and EN 312 (2010) standards were used to evaluate the particleboard. However, particleboard produced from 90 % CC and 10 % SB with cassava starch binder had the greatest modulus of elasticity (MOE) of 444.65 N/mm2 and modulus of rapture (MOR) of 10.59 N/mm2. The MOR and MOE data from this investigation allowed researchers to draw the conclusion that while the mechanical qualities of the panels improved as the fraction of CC particles increased, the panels' physical characteristics remained subpar

The use of Senilia senilis seashells as a substitute for coarse aggregate in eco-friendly concrete

This research appraised the effects of recycling senilia senilis waste seashells as a full or partial substitution for natural coarse aggregate (granite) in eco-friendly concrete production. The design mix employed a 1:2:4 concrete mix ratio for M25 grade, a w/c ratio of 0.5, river sand as fine aggregate, ordinary Portland cement (OPC) as a binder, and varying proportions of crushed seashells and granite as coarse aggregates (0:100, 10:90, 20:80, 30:70, 40:60, and 50:50). Laboratory tests revealed that workability requirements were only met with a 10%– 40% seashell addition, workability decreased with increasing seashell percentages. The compressive strength increased with curing age but decreased with the additions of seashells. The seashell-modified mixes failed to reach the design target strength for M25 concrete. Nonetheless, the 10 and 20% seashell-modified mixes achieved the required strength for M20 concrete. Split tensile strength increased with curing age for all mixes, the seashell-modified mixes yielded slightly reduced tensile strength values compared to the unmodified mix at all curing stages. However, the 10%, 30%, and 40% seashell-modified batches attained recommended split tensile strength values on the 28th day. Furthermore, high correlations were observed between the datasets of the some of the measured parameters, and variations for Split tensile strength as a function of seashell percentage and compressive strength were developed discretely by fitting the experimental data to the numerical models. Relationships were also developed for compressive strength and workability as functions of seashell percentage. Eco-friendly building construction recycling waste seashells is encouraged as it offers positive economic and environmental prospects

Effects of Dissimilar Curing Systems on the Strength and Durability of Recycled PET-Modified Concrete

Since curing remains an essential parameter that directly influences concrete strength and durability, this research aimed at evaluating the effects of water, sodium chloride (NaCl), and sodium carbonate (Na2CO3) curing regimes on concrete’s strength and durability. The design mix was composed of concrete mix ratio of 1:2:4, hydrated ordinary Portland cement with a water/ binder ratio of 0.50, river sand as fine aggregates, and varying percentages of heat-processed waste PET plastics and granite as coarse aggregates. The curing regimes’ performance was assessed by performing tests viz.: split tensile strength, compressive strength, and water absorption tests. The results showed that the curing regimes slightly influenced the split tensile and compressive strength of PET-modified concrete. The 5%-NaCl and 5%-Na2CO3 cured samples, compared to the samples cured in water, gained improved compressive strength values at all curing ages. NaCl curing further led to improved split tensile strengths for the 10 and 20% PET mixes. However, the water cured 20%-PET sample achieved the highest split tensile strength among PET-modified mixes after 28 days. PET-modified concretes attained water absorption percentages within the acceptable limit for normal concrete under the three curing regimes. Statistically, significant correlations and variations were established between the mechanical and durability properties assessed. The study concluded that the NaCl curing technique offers satisfactory performance at 10 and 20% PET replacement levels

EXPERIMENTAL AND MODELLING OF FLEXURAL STRENGTH PRODUCED FROM GRANITE-GRAVEL COMBINATION IN SELFCOMPACTING CONCRETE

The roles of coarse aggregate in concrete production cannot be over emphasized because of the volume coarse aggregate occupied in total concrete volume. The availability of locally sourced gravel aggregate (both washed and unwashed) but not put to optimal use called for this current study. The granite-gravel aggregates were varied in percentage proportions of 100/0, 90/10, 80/20, 70/30, 60/40, 50/50. A total number of 108 beams of 100×100×500 mm size were produced and cured for 28, 56 and 91 days, crushing of beams were done in line with the standard to determine the flexural strength. The MINITAB software was used to model the concrete produced. The test results indicate that 100% granite and granite-washed gravel combination up to 30% behaves satisfactorily in the reinforced concrete structure using self-compacting concrete while 40 and 50% for washed gravel showed a bit of satisfactions. Similar trend was observed for unwashed gravel of which flexural strength of the beam is still reliable at 40% unwashed gravel

Investigation of the Mechanical and Microstructural Properties of Masonry Mortar Made with Seashell Particles

In order to study the mechanical and microstructural properties of masonry mortar, combined particles of cockle and scallop seashell wastes were incorporated and analysed through destructive and non-destructive tests. River sand was replaced with the combined seashell particles (SPs) at seven mixes, viz., 0, 5, 10, 15, 20, 25, and 30% with a 0.5 constant water-to-cement ratio (W/C). A mortar mix design of M4-type of BS EN 1996-1-1 was adopted with a target compressive strength of 5.17 MPa at 28 days. The physical, chemical and mineralogy properties of the SPs were analysed through BS standard sieving, X-ray fluorescence (XRF), scanning electron microscopy (SEM), and X-ray diffraction (XRD) methods. The hardened SP-based mortars were subjected to direct compressive strength, rebound hammer, ultrasonic pulse velocity tests, and nonevaporable degree of hydration analysis. The XRF, SEM, and XRD analysis results of the SPs showed over 86% calcium oxide content, irregular and needle-like particles, and hydroxyapatite/calcium silicates, respectively. The direct compressive strength and the non-destructive test results revealed that up to 30% sand replacement with SP in masonry mortar, an improvement of 45% compressive strength could be attained over the control sample. The nonevaporable water method of the degree of hydration analysis showed that after 28 days, hydration increased considerably for the SP-blended mortars over the control, especially the SPM-30 with 30% sand replacement. Therefore, the study concludes that the investigated SPs in blended masonry mortar could benefit an eco-friendly environment and conservation of natural resources