In view of the high cost of the existing grouting materials, and at the same time the industrial production of a large number of fly ash, slag and other industrial waste can’t be effectively used. In this paper, the properties of fly ash slag cement with different ratios were studied through laboratory tests. Results show that the cement content in given conditions, with the increase of dosage of fly ash, initial setting and final setting time of cement paste with slow growth, the fluidity is growing, but the stone rate has obvious drop, on the compressive strength, the higher the slag content, is the early compressive strength, the greater the and the higher the dosage of fly ash, the late strength of cement paste were higher. This kind of grouting material has good working performance, can guarantee the project construction needs at the same time save cost, protect the environment.

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This study investigates the time-dependent mechanical properties of concrete deteriorated by the alkali-silica reaction (ASR). Previous analytical and experimental studies have indicated the positive impact of ASR gel in the cracks against mechanical damage in concrete. To study the effects of ASR gel on cracked concrete, groups of cylinder specimens with different expansion levels were prepared and tested at different material ages. The compression test results showed that the deteriorated elastic modulus of the specimens could be recovered over time. Mechanical property data from the other ASR studies were collected and assessed to observe similar trends across the literature. It was observed that the recovery of the elastic modulus also occurred in previously reported experiments. The recovery of the elastic modulus is assumed to be due to the time-dependent chemical and physical properties of ASR gel, which fills the cracks. Moreover, the data indicated that parameters other than material age and expansion could be attributed to the time-dependent mechanical properties of concrete affected by ASR.

Based on concrete carbonation test methods available and common carbonation test equipments, this article designed and developed a new concrete carbonation test equipment. The device consists of a gas storage tank and many independent small carbonation chambers. With a compact structure, the device is small, simple and practical. With its advantages of not only improving the CO2gas utilization, but also making full use of available space with the design of several smaller carbonation chambers, the device could carry out more carbonation tests without affecting their progresses. The device has a wide usage and promising future.

A sub-micron spherical powder material-micro bead, which has good water reduction, filling and enhancement effect, could be used as active mineral admixture in high-strength concrete. The affection of micro bead on the hydration temperature rise, mechanical properties, and shrinkage properties of high-strength concrete were studied, and the results showed that: micro bead could reduce the highest temperature peak of concrete, and at the low water-cement ratio, its small dosage could develop the compressive strength of concrete, and after instead of silica fume with suitable dosage, it could reduce the shrinkage of high-strength concrete.