Mechanical properties of sulphate reduction bacteria on the durability of concrete in chloride condition

S. Siswosukarto,Norzila Othman,K. Nur Rahma Putri,T. Matsumoto,A. Fajar Setiawan,H. Jonkers,A. Awaludin,Teddy Tambunan,Mohd. Irwan Juki,S. Pessiki

doi:10.1051/matecconf/201925801024

S. Siswosukarto, Norzila Othman + Show 8 more

Open Access

https://doi.org/10.1051/matecconf/201925801024

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Abstract

In construction, concrete durability is an important material globally used in engineering, material of which can be applied in the fields of specialized marine construction. The ingress of chloride into concrete causes deterioration in the concrete due to the reinforcement corrosion. Adding bacteria into concrete can improve material properties and increase durability with mechanism resist chloride ingressed in the concrete . Ingress of Chloride into the concrete of bacteria is particularly suited for applications of chloride ion penetration in concrete. The objective of the research is to determine the effect of adding bacteria into the concrete properties. The bacteria used in this research is locally isolated and enriched to the suite with the concrete environment. The type of the bacteria used is identified as Sulphate Reduction Bacteria (SRB). The SRB added into the concrete mix with concentrations of 3%, 5% and 7%. Whereas, concentration of bacteria water of cement is 0.5. The mechanical properties test conducted with 28th, 56th, 90th, 180th and 360th day of curing period. The test was using cyclic wetting and drying to study the exposure to chloride condition, such as compressive strength, tensile strength and flexural test. Cubes in the size of 150 mm × 150 mm × 150 mm were prepared for compressive strength test and cylinder 150 mm × 300 mm were prepared for the tensile strength test. The flexural strength test was on the prism in the size of 100 mm × 100 mm × 500 mm. The result of compressive strength test shows, that gave significant strength of 66.3 MPa on the 360th day. The tensile strength and flexural strength have a similar trend as compressive strength results, where both results were optimum . The tensile strength test shows that 4.52 MPa tends to control 3.96 MPa. The result of flexural strength test was 8.23 MPa for compared to control of 5.99 MPa. The overall results of the bacteria indicate promising outcome and further study on chloride condition capability is encouraging.

Highlights

In the archipelago of a long coastal zone, sea water concrete structures constantly exposed to extreme conditions, such as sea water
This condition affects the durability of the concrete structure due to environmentrelated factors such chemicals, sulfates, and chlorides contained in the sea water
The addition of bacteria (SRB) into bio-concrete has improved the concrete flexural strength by producing calcium carbonate, which reduces the pores at a faster rate of concrete correlates well with the previous study which states that the addition of bacteria has a profound impact to the flexural strength of prism by deposition of calcium lactate by bacteria [24]

Summary

Introduction

In the archipelago of a long coastal zone, sea water concrete structures constantly exposed to extreme conditions, such as sea water. Among the threatening factors such as freezing and thawing, abrasion, and corrosion of steel, the chemical attack may significantly deteriorate the concrete [1]. Chloride is considered as an extreme attack in causing the corrosion of steel in concretes. Corrosion of reinforcing steel due to chloride ingress is one of the most common environmental attacks that lead to the deterioration of concrete structures. Sulphate reduction bacteria (SRB) require dissolved oxygen to induce the corrosion cycle, as the bacteria were not able to tolerate extreme pH value. The objective of this study is to investigate the effect of SRB concentrations as influenced by water cement ratio (W/C) on the chloride attack during curing period of up to 360 days on the mechanical properties test

Isolation of sulphate reduction bacteria

Materials

Test procedure

Wetting and drying cycles on Laboratory

Compressive strength test

Tensile strength

Flexural strength

Microstructure analysis results

Findings

Conclusion

14. British Standard Institution Testing hardened concrete part 6