Flexural behavior of bamboo–fiber-reinforced mortar laminates

https://doi.org/10.1016/S0008-8846(02)00909-2Get rights and content

Abstract

This paper reports the flexural behavior of bamboo–fiber-reinforced mortar laminates. The laminate considered in this study is a sandwich plate combined with reformed bamboo plate and extruded fiber-reinforced mortar sheet. Due to its high strength to weight ratio, the reformed bamboo can remarkably strengthen the mortar and reduce the total weight of the laminate. Test results show that, for the laminates with reformed bamboo plate on the bottom as tensile layer and fiber-reinforced mortar sheet on the top as compressive layer, the flexural strength values can be improved to greater than 90 MPa.

Introduction

Bamboo is a natural perennial grass-like composite and contains ligno-cellulosic-based natural fibers. It occurs in the natural vegetation of many parts of tropical, subtropical and mild temperature regions, with about 1250 species identified throughout the world [1], [2]. Due to its superior properties like high strength to weight ratio, high tensile strength and other factors like low cost, easy availability and harmless to the environment during service, bamboo has constantly attracted the attention of scientists and engineers for use as reinforcement in cementitious composites. Recently, many researchers have tried to use bamboo as substitute of steel in reinforced concrete. Chembi and Nimityongskul [3] and Winarto [4] have reported its use in construction of water tanks. Ghavami [5] has used it for reinforcement of lightweight concrete beams. Venkateshwarlu and Raj [6] and Raj [7] have developed bamboo-based ferrocement slab elements for roofing/flooring purpose in low cost housing. Kankam et al. [8], [9] have studied its applications in reinforced concrete slabs.

However, wide applications of bamboo in civil engineering were limited by its disadvantages in the past. The principal disadvantages in its natural form are its poor bond with concrete, low modulus of elasticity, high water-absorption tendencies, low durability, and low resistance to fire. Nowadays, some of these shortcomings can be significantly improved by subjecting the bamboo to appropriate treatments [10]. In addition, when bamboo is reformed to a plate form, its performance can be improved further.

This current study investigated the preparation and flexural properties of a newly developed bamboo–fiber-reinforced mortar laminate. The laminate was a sandwich plate combined with reformed bamboo plate and extruded PVA fiber-reinforced mortar sheet. Test results showed that the reformed bamboo plate can greatly strengthen the fiber-reinforced mortar and reduce the total weight of the composite, and the flexural strength values of the laminate can be improved to greater than 90 MPa.

Section snippets

Reformed bamboo plate

Reformed bamboo plates with dimensions of 600×50×5 mm were supplied in this study. They were innovated from the raw bamboos, so that the superior properties like high tensile strength, etc. were fully made use of, and limitations such as low modulus of elasticity, lesser durability, etc. were duly taken care of. The fabricating process of reformed bamboo plate consists of three procedures. Firstly, the culms of raw bamboo were split and cut into the required sizes. Secondly, steaming to make

Experimental program

The three-point flexural test was conducted according to the requirements of ASTM D3043-87, standards methods of testing structural panels in flexure.

The flexural tests were carried out at a loading rate of 0.5 mm/min on a computer controlled MTS810 universal-testing machine with a maximum load of 100 kN. The span for specimens was set as 300 mm. The load was read from the load cell and the midspan deflection was measured by the LVDT. Plot of load versus deflection was shown on the computer

Conclusions

Due to its high strength to weight ratio, when reformed bamboo combined with fiber-reinforced mortar, it can remarkably strengthen the mortar and reduce the total weight of the composite. While the bamboo in the composite can also be stiffened by the mortar. The results of this investigation show that for the laminates with reformed bamboo plate on the bottom as tension layer and the fiber-reinforced mortar sheet on the top as compressive layer, the flexural strength values can be improved to

Acknowledgements

The authors would like to acknowledge the financial support from the Industrial Department of Hong Kong to HKUST (RI95/96.EG05-TR06). The advice and assistance from Prof. T.X. Yu and Mrs. C.M. Chan and J.K. Kim during the course of this research work are also gratefully acknowledged. The acknowledgement is also extended to the technical support of Materials and Structures Laboratory of Civil Engineering and Advanced Engineering Materials Facility.

References (10)

There are more references available in the full text version of this article.

Cited by (74)

  • Structural properties of concrete reinforced with bamboo fibers: a review

    2023, Journal of Materials Research and Technology
  • Strength of mortar reinforced with geogrid

    2023, Materials Today: Proceedings
View all citing articles on Scopus
View full text