Precast concrete materials, manufacture, properties and usage - Chapter 8

PROPERTIES AND PERFORMANCE - Kể từ khi bất kỳ tài sản duy nhất liên quan đến một hoặc nhiều đặc tính hiệu suất và ngược lại nó đã được quyết định đặt toàn bộ trong một chương ngay cả khi thực hiện chứng minh chứ không phải mở rộng. Trong thận trọng tôn trọng này cần được thực hiện là đặc điểm duy nhất và thuộc tính không đọc ra khỏi bối cảnh. Đó là nhấn mạnh trước đó nhận được tất cả mọi thứ quyền 'kết quả từ sự kết hợp của bí quyết, kỹ thuật và nghệ. | 8 PROPERTIES AND PERFORMANCE Since any single property will relate to one or more performance characteristic and vice versa it has been decided to place the whole in the one chapter even though the exercise proves rather extensive. In this respect caution should be exercised that single characteristics and properties are not read out of context. It was emphasised earlier that getting everything right results from a combination of technical knowhow and the alchemistic art of getting all the variables within specified boundary conditions. A superlative attainment in a property often lets a performance characteristic go adrift. In the following sections properties and performance of precast concrete products are discussed in the fullest way possible. A lot of what follows is basic common sense but needs to be considered in detail as all too often a particular property or performance attracts too much consideration and other aspects become overlooked. STRENGTH This is probably the property that attracts attention most commonly yet is the least necessary to worry about because the high early handling strengths required in precast production virtually always guarantee that all but the most severe specifications will be attained. Precast products are more reliable than their in situ relatives because the product per se is generally what is subjected to test proof test and not a cube or cylinder made from the same mix type test . Even large units such as panels beams and columns can be subjected to proof load tests without taking them to destruction. On the other hand low-cost products such as bricks blocks paving slabs kerbs tiles and small diameter pipes can be tested to destruction as their value is small compared to the test cost. Copyright Applied Science Publishers Ltd 1982 International Standards commonly specify bending tests and only in the case of type testing does cube or cylinder crushing or splitting come into the picture and only for bricks and most .