We wont feel unfamiliar when we talk about concrete that is composed of many raw materials. Do you realize a question that which kind of machine can produce concrete? Which machine mixes these materials so evenly? The answer is concrete mixer. Concrete mixer can not finish the task mixing materials evenly and guaranteeing concrete quality without its main devices. The first device is mixing drum. The charging and discharging devices are necessary. Concrete mixers can be classified into many types according to different properties. Its types can be named according to working property, mixing theory, installation mode, discharging and mixing drum. Certainly, different types have different merits. We take self-loading concrete mixer as an example. It is classified according to mixing theory. This kind of concrete mixer was developed at early time. Around at the beginning of 20th century, it appeared. We can imagine that this concrete mixer has simple structure, and the operation is quite c

Some unexpected obstacles will happen after concrete mixing plant production line is formally put into production because of bigger yield strength. This passage will provide some tips to solve these problems. 1. The deviation fault phenomenon of belt in concrete mixing plant. In the process of no-load or over-load, the belt conveyor may run to slightly right or left, which causes material leakage and abnormal wear and damage. As a result, the efficiency is reduced and even it affects the normal work of the whole equipment. Why do this happen? Because the external force on the belt and itself force cannot be offset, or the uneven force of tensile stress. There are many factors leading to the run-out of rubber belt. So we should solve the problem from the conveyor design, manufacture, installation, use and maintenance, etc. If the firmness on either side of the belt is not same or the height is not same, the deviation will happen. 2. Skill consideration of operators. Engineering concrete

Cement quality is directly related to construction quality and its duration, so the control of cement quality is a crucial link for concrete mixing plant.However, todays cement industry is in a mess, and the unqualified quality is common. Clinker in cement is far less than the standards. Small cement can not be called as cement, and it is just abrasive powder. Regulation on cement is in heavy deficiency. Just depending on inspection strength, setting time and the stability is not enough. 1. Clinker: calcium silicate minerals are not less than 66%, and the ratio of calcium oxide and silicon oxide is not less than 2.0, which are regulated in standards. But these data are often unqualified in cement factories that often do the strength test. 2. Clinker quantity: the common cement clinker and gypsum content should be between 80% and 95%. However, clinker content is just around 65%-70% even in big cement factories, not to mention the smaller cement factories. According to a survey, the clin

Currently, the strength of common used concrete is 20一40 n/mm. It is not difficult to produce the concrete of 80一100 N／mm if necessary. In order to lighten self-weight, concrete with light weight but high strength gets big development. Due to the continuous improvement of material strength, the application scope reinforced concrete and prestressed concrete is expanding. In recent 30 years, reinforced concrete and prestressed concrete have achieved remarkable development in long-span structure and high-rise building structure. For instance, Germany builds a roof beam of hangar with scope of 90m by adopting prestressed lightweight concrete; the scope of bridge in Japan reaches 239 m. During this period, design theory also has new development. Since the 1970s, structural reliability theory has gradually stepped into the stage of engineering practical on the basis of mathematical statistics, which makes the limit design method more improved and scientific. In the meantime, structure

Fully automatic concrete mixing plant well reduces labor amount in construction project, and more humanized designs are added in terms of using this kind of concrete mixing plant. Then, how do we rightly operate fully automatic concrete mixing plant? Which requirements should be met for operators? The so-called full automation of concrete mixing plant means that all devices such as transporting system, batching system, mixing system and discharging system can be controlled by a computer. First of all, aggregate concrete batching is transported by belt conveyor. The pump and fly ash are transmitted by screw conveyor to be weighed. Then, in the operation process of fully automatic concrete mixing plant, water and additives are weighed by electric scale. All needed concrete materials are weighed by electric scale and made a ratio according to design process. The main concrete mixer is adjusted according the materials. When production combination starts and the materials are mixed evenly,