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Calibrating Two Wood Moisture Meters for Two Species of Bamboo

Authors

Carlo Cacanando, Base Bahay Foundation Inc.
Luis Felipe López, Base Bahay Foundation Inc.
David J A Trujillo, Coventry University

Abstract

The moisture content of bamboo is critical to its treatment and use. However, determining the moisture through oven drying is impractical for most applications. Moisture meters however are able to estimate the moisture content almost instantaneously. In this study, two moisture meters, Benetech GM610 and Brookhuis FMC were calibrated for two bamboo species: Bambusa Vulgaris and Bambusa Blumeana. The tests were done on dry Bambusa Blumeana and Vulgaris, and green Bambusa Blumeana. It was found that dry bamboo could be accurately measured using these devices, while for green bamboo the results were inconclusive.

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Adoption of Grading Practices According to ISO 166242018 for Bambusa Blumeana in the Philippines a Case Study

Authors

Ray Villanueva, Kawayan Collective Bamboo Treatment Facility
Luis Felipe López, Base Bahay Foundation Inc.
David J A Trujillo, Coventry University
Marlon Tanilon, Foundation University, Dumaguete City, Philippines
Clint Absin, Foundation University
Kate Tubog, Foundation University, Dumaguete City
Oman Krish Tubat, Foundation University, Philippines, Dumaguete

Abstract

ISO 19624:2018 is the world’s first international bamboo grading standard. It contains few prescriptive clauses and is mostly written as a recipe for a national grading standard. This paper reports the initial phases of the implementation of this standard in the context of a production plant (Kawayan Collective) exploiting Bambusa blumeana harvested in The Philippines. The team undertook the initial evaluation (i.e. characterization) of B. blumeana harvested from six sites. 123 culms were geometrically and mechanically characterised, as required by ISO 19624. Current visual grading rules used at Kawayan Collective have been recorded as well as their associated rejection rates and resulting associated cost of this rejection. Early findings from the initial evaluation are discussed.

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Establishing the Characteristic Shear Strength of a Local Bamboo Species: Bambusa Blumeana (Kawayan Tinik)

Authors

Brian Bautista, De La Salle University
Lessandro Estelito O. Garciano, De La Salle University
Luis Felipe López Base Bahay Foundation Inc.

Abstract

The mechanical properties of a structural material such as flexure, shear, and compressive strengths are needed in the structural design process. Unfortunately, published studies of the shear strength of an important local species: Bambusa blumeana (Kawayan Tinik) are limited. The authors focused on this property since joint connections are possible points of failure when a bamboo structure is subjected to extreme loads. The latest ISO 22157-1 test protocol and ISO 12122-1 were used to establish the shear strengths of twelve bamboo samples from Laguna. The results show that the average shear and characteristic shear strengths of Kawayan Tinik are 12.2 MPa and 9.56 MPa, respectively. Since testing facilities are limited at the site, the authors also proposed a linear model to estimate the shear strength of bamboo using the physical properties derived from the tests.

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Comparative Analysis of Shear Strength Parallel to Fiber Of Different Local Bamboo Species in the Philippines

Authors

Brian Bautista, De La Salle University
Lessandro Estelito O. Garciano, De La Salle University
Luis Felipe López, Base Bahay Foundation Inc.

Abstract

There are limited published studies related to the mechanical properties of bamboo species in the Philippines. In this study, the shear strength properties of some economically viable bamboo species in the Philippines were properly characterized based on 220 shear test results. The rationales for selecting this mechanical property are the following: (1) Shear strength, parallel to the fiber, has the highest variability among the mechanical properties; and (2) Shear is one of the governing forces on joint connections, and such connections are the points of failure on bamboo structures when subjected to extreme loading conditions. ISO 22157-1 (2017) test protocol for shear was used for all tests. The results showed that Bambusa blumeana has the highest average shear strength, followed by Gigantochloa apus, Dendrocalamus asper, Bambusa philippinensis, and Bambusa vulgaris. However, comparative analysis, using One-way ANOVA, showed that shear strength values among these bamboo species have significant differences statistically. A linear regression model is also established to estimate the shear strength of bamboo from its physical properties. Characteristic shear strength is also determined using ISO 12122-1 (2014) for future design reference.

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Establishing the Strength Parameters Parallel to Fiber of Dendrocalamus asper (Giant Bamboo)

Authors

Anika De Jesus, De La Salle University
Lessandro Estelito O. Garciano, De La Salle University
Luis Felipe López, Base Bahay Foundation Inc.
Diane Megan Co Ong, De La Salle University
Ma Chrissel Paula Roxas, De La Salle University
Mikhaela Andrea Isidro Tan, De La Salle University
Richard De Jesus, De La Salle University

Abstract

The supply of timber is becoming scarce in the Philippines. Dendrocalamus asper (or giant bamboo) is a candidate for safe, sustainable, and low-cost alternative housing to timber. However, its mechanical properties are yet to be established. In this paper, the compressive strength, shear strength, and tensile strength parallel to the fiber of Dendrocalamus asper are determined using ISO 22157 and ASTM D143 tests. For the latter, a slight modification of ASTM D143 was employed. The result yielded an improved tensile strength parallel to fiber. The tensile strength was also tested using a modified version of ASTM D143, wherein the length of the test piece was changed to ensure failure within the gauge length. Two hundred (200) samples of 2m-long Dendrocalamus asper (giant bamboo) poles were prepared and used for testing. Equipment was fabricated to the dimensions of the test sample. The obtained tensile strength parallel to fiber using the ISO 22157 method had an average strength of 312.78 MPa for specimens with attached hardwood tabs and 424.43 MPa for specimens with attached softwood tabs while with the Modified ASTM D143-94 method, the average strength was 269.86 MPa. The shear strength parallel to the fibers had an average strength of 10.64 MPa at the internode and 11.87 MPa at the node. Lastly, the compressive strength parallel to the fibers had an average strength of 63.42 MPa at the internode and 55.55 MPa at the node.

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Assessment of testing protocols for bamboo for tension parallel to the fiber

Authors

Martin Aldrin De La Cruz, De La Salle University
Luis Felipe López, Base Bahay Foundation Inc.
Richard De Jesus, De La Salle University
Lessandro Estelito O. Garciano, De La Salle University

Abstract

To determine tension parallel to fiber properties of Bamboo, one can employ ISO 22157. However, several studies highlighted some challenges in using the method such as premature failure of testing due to force at clamping and slipping failure at the grips. Hence, this study aimed to look for a solution to address these challenges. This study investigated, both qualitatively and quantitatively, three testing protocols in determining bamboo’s tensile strength parallel to fiber-(1) ISO 22157, (2) a modification of ASTM D143, and (3) Pittsburgh Method. The success rate, test duration, load rate and transmission, specimen preparation, equipment fabrication, and execution of the three protocols were compared. The physical properties of bamboos, such as moisture content, density, and shrinkage, were also measured in the study. The results of the study showed that the modified ASTM D143 test is the most viable method to use in testing the tensile strength parallel to fiber of bamboos. Modified ASTM D143 produced the highest tensile strength with value equal to 100.36 MPa, compared to specimens tested under ISO 22157 with tensile strength only reaching 94.11 MPa, while Pittsburgh Test produced the lowest tensile strength of 76.78 MPa. Modified ASTM D143 also yielded the lowest confidence interval which implied good consistency. Modified ASTM D143 is the recommended test protocol based on the results of this study as it gained the highest success rate during testing, lowest testing duration, and the easiest to execute.

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