Bamboo Guadua Research Articles

Manufacture and mechanical analysis of composites of bamboo Guadua angustifoliaKunth

En esta investigación fueronfabricados compuestos de partículasde Guadua angustifoliaKunth con tamaños de 500 μm y 300 μm con matriz polimérica. El objetivo fue evaluar las propiedades físico-mecánicas de los compuestos y compararlas con los resultados obtenidos en compuestos comerciales. Las propiedades mecánicas fueron analizadasusandoun diseño factorial general con un factor, dos niveles y tres variables de respuesta. La adhesión de las partículas de guadua demostrómayor resistencia a esfuerzos de tracción ymódulo de elasticidad frente al obtenido en compuestos comerciales. Los compuestos de guadua presentaronmayor resistencia a la penetración debido almenor volumen de espacios vacíos entre partículas. Enpruebas de absorción de agua, los compuestos de guadua tuvieron hastaun 69 % de absorcióny 16 % de incremento de espesor en 24 h frente a 86 % y 22 % respectivamente en compuestos comerciales. Asimismo, en pruebas mecánicas elcompuesto de guadua 500 μm fueun 23% de mayor resistenciaen flexiónfrente al compuesto comercial. Además, los compuestos guadua 500 μm y 300 μm tuvieron mayor resistencia a la tracción hasta en 57% y 32% respectivamente en comparación al compuesto comercial. En pruebas de dureza los compuestos de guadua mostraron mayor resistencia a la penetración frente al compuesto comercial.

Compression resistance of short members as the basis for structural grading of Guadua angustifolia

This study develops the structural grading of Guadua bamboo culms subjected to axial compression. Both strength and capacity grading methods are explored. Several candidates for Indicating Properties (IPs) were measured and calculated. The strongest coefficients of determinations for structural grading were related to densities [e.g., (conventional) density (ρ) and linear mass (q)]. Density (ρ) is best IP for strength grading if the culm section is taken as a hollow circle. Alternatively, linear density or linear mass (q) provides higher coefficients of determination when used for capacity grading. By using intervals of each indicating property (IP), several structural grades were developed. Each grade has its Grade Determining Properties (GDPs) include mean compressive strength (fc) or load carrying capacity (Fu), five percent exclusion limit (R0.05), and characteristic structural property (Rk). The latter could be used in structural design. As bamboo is a hygroscopic material, the IP should be adjusted into standardized moisture content (12% Mc). The moisture content effect on compressive strength and capacity should also be measured to increase the reliability of estimation if densities (ρ or q) are chosen as the IPs. Since external diameter can infer the linear mass (q) and is also significantly correlated with wall thickness (t), average external diameter (D) may also be used as the sole IP in capacity grading. Structural grading can reduce the variability of Guadua’s structural properties since it classifies the culm into several suitable grades.

Fine-scale effects of bamboo dominance on seed rain in a rainforest

Bamboo dominance in tropical forests drives changes in floristic composition and vegetation structure. However, the role of bamboo dominance over ecosystem functions - including those related to forest regeneration - has received less attention. This study evaluated the fine-scale effects of the dominance of native bamboo Guadua weberbaueri Pilg. (Poaceae) on seed rain in a terra-firme forest in the southwest of the Brazilian Amazon to understand how bamboos remain a dominant element where they occur. We tested the hypothesis that bamboo dominance (i) reduces seed diversity and biomass and (ii) changes floristic composition and frequencies of seed dispersal mechanisms. For one year, we sampled seeds from seed rain in adjacent bamboo-dominated (BD) and bamboo-free (BF) environments in a forest without major anthropogenic disturbances. We found lower seed species richness in the BD environment and similar seed biomass between BD and BF. In addition, the seed species composition differed between BD and BF, with higher frequency of abiotic mechanisms to seeds dispersal in BD. We conclude that the dominance of bamboos acts as a filter for species that arrive via seed rain, modifying the floristic composition and dispersal mechanisms and, consequently, the dynamics of natural regeneration processes of terra-firme forests in the Amazon. This process can promote the permanence and expansion of the distribution area of bamboos in tropical forests.

Implementation of bamboo and monkey-pot traps for the sampling cavity-breeding mosquitoes in Darién, Panama

Despite the importance of Aedes, Haemagogus and Sabethes in the transmission of yellow fever virus (YFV) and the public health impacts of recent YFV epidemics in the Americas, relatively little has been reported on the biology and ecology of these vectors. Many Aedes, Haemagogus and Sabethes spp. in the American tropics inhabit and develop in the forest canopy and are difficult to sample with conventional entomological surveillance methods. We tested the utility of two previously developed phytotelmata-style oviposition traps (bamboo Guadua angustifolia) and (monkey-pot Lecythis minor), for collecting immature forms of these mosquitoes in a forest near the community of Aruza Abajo, Darién Province, Panama. Our results showed distribution of mosquito species emerging from the two types of traps was found to be significantly different (X2 = 210.23; df = 14; P < 0.001), with significantly greater numbers of Sabethes (Peytonulus) aurescens (Lutz) and Sabethes (Peytonulus) undosus (Coquillett) emerging from the bamboo traps. More females of Sabethes (Sabethes) cyaneus (Fabricius) were captured in the monkey-pot traps, although the difference was not significant. No differences were observed in the average time to emergence for the two traps. These results suggest that various phytotelmata-style traps, including monkey-pot and bamboo, could be used to improve entomological surveillance of YFV vectors in the American tropic.

Variability of Physical and Chemical Properties of TLUD Stove Derived Biochars

Biochar is a carbon-rich organic material, obtained by the thermochemical conversion of biomass in an oxygen-limited environment, used as a soil amendment to stimulate soil fertility and improve soil quality. There is a clear need in developing countries for access to low cost, low technology options for biochar production, for example, top-lit updraft (TLUD) stoves, which are popular and spread worldwide. However, TLUD biochars are inevitably very variable in their properties for a variety of reasons. We present laboratory triplicate tests carried out on TLUD biochars obtained from waste pinewood and a Guadua bamboo. Analyzed properties include specific surface area (A-BET), porosity, skeletal density, hydrophobicity, proximal and elemental composition, cation exchange capacity (CEC), relative liming capacity and pH. SEM images of the bamboo and wood biochars are compared. The biochars were mixed with composted human excreta at 5% and 10% biochar content, and available water content (AWC) was analyzed. Operating temperatures in the TLUD were recorded, showing different behaviors among the feedstocks during the process. Differences in operating temperatures during charring of the bamboo samples seem to have led to differences in A-BET, hydrophobicity and CEC, following unprecedented trends. For the mixtures of the biochars with compost, at 5% biochar no significant differences were observed for AWC. However, in the 10% biochar mixtures, bamboo biochar showed an unexpectedly high AWC. Overall, variations of chemical and physical properties between bamboo biochars were greater, while pinewood biochars showed similar properties, consistent with more homogeneous charring temperatures.

Oxidative pyrolysis of Guadua angustifolia Kunth

This is a study of the behavior of the species of bamboo Guadua angustifolia Kunth during oxidative pyrolysis. Thus, thermogravimetric analysis of G. angustifolia combustion in an oxygen flow rate of 50 cm3/min and at a heating rate of 10 ºC/min was carried out. Moreover, the combustion profile was compared with the pyrolysis profile of G. angustifolia in nitrogen, using the same flow rate and the same heating rate. For this type of bamboo, devolatilization during combustion (oxidative pyrolysis) is boosted by the heterogeneous oxidation of the pyrolyzable fraction of this material. Therefore, the emission of volatiles is highly accelerated. This fact may be due to both the use of an oxygen flow and the inorganic composition of G. angustifolia, which contains high concentrations of potassium. This potassium may act as a catalyst that weakens organic matter bonds by an oxygen transfer mechanism. This behavior is not observed for all types of biomass. Therefore, it is likely that inorganic matter of biomass plays an important role in the way its oxidation occurs, which has a significant influence on the choice of the most suitable process for its valorization.

Description of a new and highly distinctive genus and species of Euptychiina (Lepidoptera: Nymphalidae: Satyrinae) from the Brazilian southern Amazon

A new genus and species of Euptychiina (Satyrinae), Cristalinaia vitoria Mota, Zacca & Freitas gen. et sp. nov., is described based on three specimens collected in the region of the Cristalino River, Alta Floresta, Mato Grosso, Brazil. This rare species is known only from this region, where it flies inside the dense bamboo patches typical of that area. The last instar larva and the pupa are described; the larva was observed feeding on mature leaves of the common bamboo Guadua aff. paniculata Munro.urn:lsid:zoobank.org:pub:D61EDE8D-CAE9-41C6-B24D-BB789873566E

Numerical model of cracking pattern in laminated bamboo specimens under tensile and shear loads

This work describes a two-dimensional numerical model that allows detecting the appearance of cracks and calculating their propagation in elements made of laminated bamboo, under tension and shear. This composite material has long parallel strong cellulose fibers embedded in a weak lignin matrix. The mechanical model that represents the failure and fracture process of laminated bamboo is still unknown. This numerical model simulates localized strains, showing the beginning and progression fracture in the material. The model is based on a two-dimensional scheme for plane stresses, using the finite element method. A one-dimensional plasticity constitutive model, based on Weibull probability distribution, is used to describe the mechanical response of the fibers, and a continuum damage constitutive model controls the behavior of the matrix. The homogenization process is done with the rule-of-mixtures, and vanishing fiber diameter simplification. Continuum strong discontinuities approach is taken as a technique to detect a jump in the displacement field, during the fracture process. This numerical model is used to simulate the failure on tensile and shear tests of laminated bamboo Guadua angustifolia, which were then compared to experimental findings. The results show that the numerical model detects the same crack patterns obtained in tests.

Floristic structure and composition of Guadua forests in the Colombian coffee region1

ABSTRACT In the coffee region (900-2,000 m a.s.l.) of the Colombian Andes, the forest remnants correspond mainly to fragments dominated by the bamboo species Guadua angustifolia Kunth (Guadua). These highly fragmented forests are found in landscapes with a high degree of transformation due to the agricultural activity and urban expansion. With the purpose of contributing to the knowledge of the ecological characteristics of these forests, the floristic structure and composition (alpha, beta and gamma diversity) of seven forest fragments located in the middle (Quindío) and lower basins of the La Vieja river (Risaralda) were studied. A total of 70,961 individuals and 172 species belonging to 54 families were found. Fifty percent of the families were represented by only one species, and the families Araceae and Leguminosae showed the highest taxonomic richness, respectively with 21 and 14 species. The diversity indices for these forests revealed values comparable to those of tropical forest ecosystems (Shannon-Weiner values between 3,167 and 3,798). Likewise, the cluster analysis (based on Euclidean distances) showed that the stands present a similarity below 0.65 (65 %), associated with the 35 species reported, in seven fragments that characterize a varied floristic composition. This finding implies that these fragments should not be seen as isolated units, but as sites embedded in a diverse regional landscape. This represents important habitats for these species, which are capable of maintaining significant levels of diversity, even under management conditions.

New aquatic species of Megaselia Rondani from Bolivia (Diptera: Phoridae)

Ten aquatic species of Megaselia Rondani (1856) are reported from the internodes of the large bamboo Guadua angustifolia var. chacoensis in Bolivia. Megaselia aquatica sp. n., and M. imitatrix Borgmeier (1969) are named and seven species given code letters as their males remain unknown. Five of these species closely resemble the distinctive M. imitatrix. The eggs of species C, in addition to a subterminal plastron, uniquely have the rest of the egg covered in fine hairs. Three additional Megaselia species reported from bamboo or other phytotelms in the Americas, Megaselia hansonix Disney (2009), M. rufipes (Meigen) (1804) and M. scalaris (Loew) (1866) are illustrated. A key for Megaselia from the Americas reported from aquatic situations is presented.

Composites of Portland cement and fibers ofGuadua angustifoliaKunth from Colombia

The main objective of this work is to study the flexural mechanical behavior of fiber-reinforced composites made of ordinary white Portland cement combined with Guadua bamboo from Colombia (known as Guadua angustifolia Kunth or just guadua). Fibers were carefully removed from the stem with a knife in a manual process, and then samples with 0.0, 4.0, and 8.0 wt% of fibers were fabricated. No further treatment was used in order to make the process as simple and inexpensive as possible for applications in the construction and building materials industry. Mechanical and structural characterization was analyzed by optical microscopy and scanning electron microscopy. Density compressive strength and Weibull distribution graphs were included in this work. The results show that flexural strength increases as the fiber content is increased. They also show a very good impregnation of the cement in the fibers, which validated the use of fiber from the bamboo culm. It is feasible that these composites can be used in the construction and building materials industry on a large scale for noncritical ultimate strength applications because of the low costs associated with processing the fibers.

Steam gasification behavior of tropical agrowaste: A new modeling approach based on the inorganic composition

The steam gasification and co-gasification reactivity and kinetics of coconut shells, oil palm shells and bamboo guadua were studied from an isothermal thermogravimetric analysis, with temperatures ranging from 750 °C to 900 °C, and steam partial pressures from 3 to 10 kPa. In the analyzed experimental range, inorganics were identified as the most influential parameter in biomass reactivity and kinetics. Accordingly, a new modeling approach is proposed to predict the gasification behavior of lignocellulosic agrowaste based on their inorganic composition. A good agreement between the experimental and modeled data was found, showing that the proposed approach is suitable for the description and prediction of the gasification behavior of biomasses with different macromolecular structure and within a wide range of inorganic composition, and H/C and O/C ratios near 1.5 and 0.8 respectively. This kinetic model could constitute a valuable tool for reactor design and scale-up of steam gasification facilities using tropical lignocellulosic feedstocks.

Experimental and numerical modeling of shear behavior of laminated Guadua bamboo for different fiber directions

The shear strength and the crack pattern of laminated Guadua bamboo (LGB) are studied in this work, by means of both experimental tests and numerical simulation, considering the three different orthogonal directions of the fibers: (i) when the fiber is parallel to the loading direction, (ii) when the fiber is perpendicular to the loading direction without crossing the reduced area plane, and (iii) when the fiber is perpendicular to the loading direction and crossing the reduced area plane. The slats orientation and disposition in LGB were experimentally studied, when the contact surface between slats is parallel to the reduced area plane and when it is perpendicular. Likewise, the cases when the contact surface between slats matches with the reduced area plane is tested and when it is not. The numerical model of finite elements is based on the continuum strong discontinuity approach for composite materials and the Weibull probability model for the failure progressive of fibers. The crack direction obtained in the numerical simulation is approximately equal to the one observed in the corresponding experimental test, regardless of the disposition slats. LGB with fibers parallel to the loading direction exhibits a crack that matches with the reduced area plane. In LGB with fibers perpendicular to the loading direction that do not cross the reduced area plane, the crack is inclined 45 degrees with respect to loading direction. In LGB with fibers perpendicular to the loading direction and crossing the reduced area plane, several cracks are made up perpendicularly to loading direction and parallel to the fiber orientation.

Seedling Community in a Patchy Tropical Vegetation Under the Influence of Bamboos

As a group adapted to invade disturbed sites, bamboos can dominate extensive areas and, thus, alter vegetation structure and dynamics. However, the effect of bamboo expansion associated to human activity on seedling communities in tropical forests remains poorly known. We investigated the correlation of the native bamboo Guadua tagoara presence for a year on the abundance, richness, diversity, dominance, evenness, emergence, mortality, and growth of the first months of the native seedlings establishment in an Atlantic forest area, São Paulo State, Brazil. Bamboo presence favored the initial establishment of the palm Euterpe edulis seedlings but altered seedling community structure as a whole. Species richness did not differ between bamboo and nonbamboo dominated habitats, but abundance, diversity, and evenness did. Bamboo habitats showed higher seedling abundance, emergence, and mortality than in habitats without bamboos. However, diversity was lower in these habitats. Our results shed light on the role of bamboo presence in limiting early establishment of native seedlings but favoring the first months of establishment of E. edulis, the dominant species in bamboo habitats (70%). Therefore, the monitoring of more specific variables could be included (i.e., bamboo culm density, soil type, decomposition of organic matter, fauna living, or foraging in bamboos) in future studies to better understand the consequences of bamboo dominance on the recruitment and dynamics of tropical forests biodiversity in the long term.

Empirically derived connection design properties for Guadua bamboo

Three connection design properties (dowel embedment strength, slip modulus and screw withdrawal capacity) were determined for one species of bamboo (Guadua angustifolia Kunth) using experimental methods adopted from timber engineering. 151 embedment strength and slip modulus tests were undertaken using smooth dowels with diameters ranging from 3 to 16 mm, whilst 240 screw withdrawal tests were undertaken using 3.5–5 mm diameter self-tapping screws. Using regression analysis, predictive equations for the three connection design properties were derived, based on fastener diameter, density and bamboo wall thickness. Coefficients of determination (R2) ranged from 0.45 to 0.82. The predictive equations for embedment strength and screw withdrawal were adapted to output characteristic values and then compared to similar equations derived for timber contained in Eurocode 5, the latter would seem inappropriate for bamboo.

Kinetic Analysis of Tropical Lignocellulosic Agrowaste Pyrolysis

The thermal behavior of three Colombian agricultural residues was studied by non-isothermal thermogravimetric analysis (TGA) at various heating rates. An approach using a combined kinetics parallel reaction model and model-free isoconversional methods proved to be suitable to determine the pyrolysis kinetic parameters of biomasses with different macromolecular composition and H/C and O/C ratios near 1.5 and 0.8, respectively. Fraser-Suzuki functions representing the derivative TGA (DTG) of hemicellulose, cellulose and lignin showed a very good agreement with the experimental data. The calculated apparent activation energy of biomass pseudo-components evidenced no dependence on the reaction extent in all the conversion range, validating the use of master plots for decomposition mechanism identification. Pseudo-hemicellulose, pseudo-cellulose, and pseudo-lignin showed to be close to a second-order kinetic model, a random scission, or an Avrami-Erofeev model and a high-order kinetic model, respectively. Comparing the three feedstocks, the apparent activation energy of the pseudo-components was in the order: bamboo guadua E a < coconut shells E a < oil palm shells E a . The results show that even when sample elemental composition is very similar, macromolecular constituents, in particular lignin, could have an impact in the biomass decomposition rate and apparent activation energy. For the three studied materials, the model fitting error below 10% showed that the calculated kinetic parameters are suitable for the description and prediction of the biomass thermal decomposition.

Bio-based composites from agricultural wastes: Polylactic acid and bamboo Guadua angustifolia

Biopolymers as polylactic acid (PLA) have some drawbacks in processing and the final product is characterized by a high permeability to steam/gases and low thermal and mechanical resistance. The addition of reinforcement materials in the biopolymer matrix provides opportunities to minimize these disadvantages. Thus, this research focuses on the inclusion of non-wooden lignocellulosic fillers from bamboo Guadua angustifolia in a polymer matrix obtained from PLA. Three types of fillers were applied: sawdust, fiber from a Kraft process, and fiber with low lignin content. The blends of PLA reinforced with 5% organic fillers were performed on a torque rheometer at temperatures between 170 to 200℃ with the addition of glycerol as plasticizer and viscosity reducer of the system and maleic anhydride as compatibilizer. The evaluation on rheological, thermal, mechanical and morphological properties were investigated by rotational rheometry, differential scanning calorimetry (DSC), universal testing machine, wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The results showed that the inclusion of the lignocellulosic material generated a positive response in obtaining polymeric biocomposite. The use of fibers subjected to a process of delignification with bleaching sequences OQPoPWa resulted in a greater influence on the mechanical strength, an adequate distribution of the fibers in the PLA matrix and the viscosity of the mixture.

Guadua bamboo In pedestrian bridges

&lt;p class="p1"&gt;When discussing pedestrian bridges, it is always useful to consider the latest work done in Colombia. These innovative constructions not only make it possible to cross rivers and roads, but also show how competitive this material is in ecological engineering. The spread of this type of construction throughout the country indicates that Guadua bamboo is already a part of Colombian culture, and that its fresh style is no longer associated only with poverty and social improvement projects. Furthermore, it shows that this material is a perfectly feasible option for a country such as ours, which is exposed to landslides, flooding and earthquakes. &lt;/p&gt;&lt;p class="p1"&gt;Although pedestrian bridges were initially built to shorten distances and overcome natural barriers, during the last several decades they have also become necessary to safeguard pedestrians who have to walk in areas of very high urban growth. However, in spite of the existence of alternative solutions to the same problem, almost all such solutions are postponed, in that they normally involve a State investment. &lt;/p&gt;&lt;p class="p1"&gt;This article addresses a construction technique which originated in South American indigenous populations. Although it was forgotten by several generations, this technique, which has been updated, has multiple benefits. By injecting concrete in bamboo internodes it is possible to build structures that are in harmony with current needs, as well as bridges with more lighting Most importantly, this makes low-impact construction accessible to small communities or private businesses with limited resources. &lt;/p&gt;

Bamboo thickets alter the demographic structure of Euterpe edulis population: A keystone, threatened palm species of the Atlantic forest

The rapid spread of bamboos can strongly affect forest structure by interfering plant regeneration and reducing local biodiversity. Considering that bamboos exert a negative influence on the plant community, our main goal was to investigate how this influence manifests at the population level. We compared the demographic structure of the threatened palm Euterpe edulis between bamboo and non-bamboo dominated patches within the Atlantic forest. In the study site, the native bamboo Guadua tagoara has created a marked patchiness and heterogeneity in the vegetation. Plots were set up randomly in bamboo and non-bamboo patches and the heights of all E. edulis individuals were measured. Data from canopy openness and litter depth were collected for both patches. Greater number of E. edulis was recorded in bamboo patches. However, frequency distribution of the height classes differed between patches revealing a predominance of seedling and sapling I classes in bamboo patches, in comparison to a more evenly distribution of height classes in non-bamboo patches. The canopy in bamboo patches was more open and the litter depth was thicker. Our analyses evidenced G. tagoara is functioning as a demographic bottleneck of natural population of E. edulis by arresting its later stages of regeneration and in high densities that bamboos may limit recruitment of this palm species.

Thermal conductivity of engineered bamboo composites

Here we characterise the thermal properties of engineered bamboo panels produced in Canada, China, and Colombia. Specimens are processed from either Moso or Guadua bamboo into multi-layered panels for use as cladding, flooring or walling. We utilise the transient plane source method to measure their thermal properties and confirm a linear relationship between density and thermal conductivity. Furthermore, we predict the thermal conductivity of a three-phase composite material, as these engineered bamboo products can be described, using micromechanical analysis. This provides important insights on density-thermal conductivity relations in bamboo, and for the first time, enables us to determine the fundamental thermal properties of the bamboo cell wall. Moreover, the density-conductivity relations in bamboo and engineered bamboo products are compared to wood and other engineered wood products. We find that bamboo composites present specific characteristics, for example lower conductivities—particularly at high density—than equivalent timber products. These characteristics are potentially of great interest for low-energy building design. This manuscript fills a gap in existing knowledge on the thermal transport properties of engineered bamboo products, which is critical for both material development and building design.