Ảnh hưởng của tỉ lệ độ cứng dọc trục cốt FRP đến ứng xử uốn của dầm bê tông đặt cốt lai FRP/thép=Effect of axial stiffness ratio of frp bar on the behvior of hybrid frp/steel reinforced concrete beams

0 Người đánh giá. Xếp hạng trung bình 0

Tác giả: Văn Tuyên Bùi, Đức Sỹ Nguyễn

Ngôn ngữ: vie

Ký hiệu phân loại:

Thông tin xuất bản: Tạp chí Xây dựng, 2024

Mô tả vật lý: tr.96

Bộ sưu tập: Metadata

ID: 478667

Thêm vào giỏ

Bài báo này trình bày kết quả nghiên cứu về ảnh hưởng của tỉ lệ độ cứng dọc trục của cốt thanh polyme cốt sợi (FRP) đến mômen gây chảy cốt thép và khả năng chịu lực trên tiết diện thẳng góc của dầm bê tông đặt cốt lai FRP/thép. Để mô phỏng ứng xử của dầm, tác giả đã xây dựng mô hình dầm đặt cốt lai kết hợp từ các thanh cốt sợi thuỷ tinh và thanh cốt thép trên phần mềm Lira Sapr. Kết quả mô phỏng ứng xử của dầm được kiểm chứng bằng kết quả nghiên cứu thực nghiệm. Dựa trên mô hình dầm trên phần mềm Lira-Sapr, tác giả đã phân tích ứng xử của ba nhóm dầm khác nhau về hàm lượng cốt thép, hàm lượng cốt FRP và mô đun đàn hồi của cốt FRP. Từ đó đánh giá ảnh hưởng của tỉ lệ độ cứng dọc trục của cốt FRP đến mô men gây chảy cốt thép và khả năng chịu lực của dầm. Kết quả nghiên cứu cho thấy, khi cố định hàm lượng cốt thép, tăng tỉ lệ độ cứng dọc trục của cốt FRP từ 1.06 đến 1.67 làm tăng mô men gây chảy cốt thép của dầm 51% và tăng khả năng chịu lực của dầm đến 87%, đồng thời khả năng chịu lực và mô men gây chảy cốt thép của các dầm sử dụng các loại cốt FRP với mô đun đàn hồi khác nhau nhưng có cùng tỉ lệ độ cứng dọc trục là như nhau. Ngược lại, khi cố định hàm lượng cốt FRP, việc tăng tỉ lệ độ cứng dọc trục của cốt FRP từ 1.11 đến 1.67 sẽ làm giảm mô men gây chảy cốt thép 73.3% và giảm khả năng chịu lực của dầm 35.4%. Từ khóa: Dầm
bê tông cốt thép
FRP
cốt lai
Lira-Sapr
độ cứng dọc trục.This paper presents the research results on the influence of the axial stiffness ratio of fiber-reinforced polymer (FRP) bars on the steel yielding moment and the load-bearing capacity of the cross-section of FRP/steel hybrid reinforced concrete beams. To simulate the behavior of the beam, the author constructed a hybrid reinforcement beam model combining glass fiber bars and steel bars using the Lira-Sapr software. The simulation results of beam was verified with experimental research results. Based on the beam model in Lira-Sapr, the author analyzed the behavior of three different beam groups concerning steel reinforcement ratio, FRP reinforcement ratio and the elastic modulus of FRP, thereby assessing the impact of the FRP axial stiffness ratio on the steel yielding moment and the load-bearing capacity of the beam. The research results show that, with a fixed steel reinforcement ratio, increasing the FRP axial stiffness ratio from 1.06 to 1.67 increases the steel yielding moment of the beam by 51% and the load-bearing capacity by up to 87%. Simultaneously, the load-bearing capacity and steel yielding moment of beams using different types of FRP with various elastic moduli but the same axial stiffness ratio are equal. Conversely, with a fixed FRP reinforcement ratio, increasing the FRP axial stiffness ratio from 1.11 to 1.67 decreases the steel yielding moment by 73.3% and the load-bearing capacity of the beam by 35.4%. Keywords: Beam
reinforced concrete
FRP, hybrid reinforcement
Lira-Sapr
Axial stiffness.

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