Composition and early-age temperature regime in massive concrete foundation

Abstract

The usage of monolithic concrete technology in massive structure construction has created a need for a more detailed design focused on crack control. In this study, the American standard ACI 211.1-09 and absolute volume method were used to determine the composition of heavy weight concrete for the high-rise building foundation. The concrete block temperature behavior has been analyzed by a three-dimensional thermal model in program Midas Civil. The conducted studies' result provided the possibility of obtaining heavy weight concrete from Vietnam local raw materials regarding to the concrete mixture workability of 16 cm standard cone, compressive strength of 42.3 MPa and average tensile strength of 3.5 MPa at the age of 28 days. According to the model analysis results, the maximum temperatures of the massive concrete foundation at the first (after 72 hours) and second pour (after 144 hours) from the beginning of construction are respectively 55.70C and 65.50C. In addition, the temperature differences at the core of each concrete pours with respect to the concrete outer portion, which induces a risk of through cracking in structure body or surface were determined.

Mô hình dự đoán toán học về chế độ nhiệt trong cấu kiện bê tông khối lớn có sử dụng hệ thống ống làm lạnh

“…Các vết nứt xuất hiện không chỉ ảnh hưởng đến tuổi thọ kết cấu mà còn ảnh hưởng đến quá trình khai thác sau này. Đặc biệt, trên thế giới cũng như ở Việt Nam, vấn đề kiểm soát nứt do nhiệt thủy hóa xi măng đối với kết cấu BTKL được đông đảo các nhà khoa học quan tâm và nghiên cứu [5][6][7][8].…”

Evaluating the Effectiveness of Continuous Composite Beams for Steel-Concrete Bridges and Control Concrete Cracks of the Supports at an Early Age

“…The transverse beams at the abutments and the supported reinforced concrete sections after continuous composite beams by pouring concrete. At the early age day in concrete at the supports and the abutments occur thermal cracking of cement hydration [8][9][10][11][12]. The present study aims to evaluate the effectiveness of continuous composite beams for steel-concrete bridges and control of cracking of concrete at the supports at an early age with building condition in Vietnam.…”