jtj034-93公路路面基层施工技术规范英文版

jtj034-93公路路面基层施工技术规范英文版内容摘要：

construction method may make reference to this Code. 7/151 For ordinary highway at secondclass or below, the clay cement base layer and subbase can be constructed by the roadmixing method. However, for secondclass highway, special purpose stabilized clay mixer shall be used. For firstclass highway and speedway, except the lower layer of the subbase directly laid on the clay base, which can be constructed with stabilized clay mixer and roadmixing method, all other stabilized clay layers above it shall be constructed by blending the mixture with the centralized shop mixing method and spreading the base mixture with spreading machine. The clay cement base layer and subbase shall not be constructed by the manual mixing method. Material Clay Any clay that can be economically crushed can be stabilized with cement. In actual practice, the following stipulations shall be plied with: For secondclass highway and below (1) When clay cement is used as subbase, the maximal size of grain shall not exceed 50mm① , the clay grain position shall fall within the range listed in Table , the coefficient of uniformity of clay② shall be greater than 5, the liquid limit of finegrained clay shall not exceed 40, and the plasticity index shall not exceed 17③ . In practical application, clay with coefficient of uniformity larger than 10 and plasticity index smaller than 12 should be selected. Clay plasticity index larger than 17 should be stabilized with lime or with cement and lime together. Table Grain position range for aggregates that can be stabilized with cement (Subbase of secondclass highway and below) Mesh size(mm) 50 5 Pass percent (weight) 100 50～ 100 15～ 100 0～ 50 0～ 30 Notes: ○ 1 refers to square hole screen。 in case of round hole screen, the maximal size can be ~ times the listed value, same as below. [Remark] All screens used in tables and figures of this Code are square hole screens. Where corresponding square hole screen is not available, two gradation curves may first be drawn on the logarithmic coordinate system for grain position. Then identify the position or point of the required screen hole, make a perpendicular line from this point to intersect with the two curves (as showen with figure ). Draw horizontal lines from these intersection points, which then interest with the vertical coordinate. The pass percent of the required grain size is thus obtained. ○ 2 The ratio of the screen hole size with 60% pass to that with 10% pass is referred to as coefficient of uniformity of clay. ○ 3 This stipulation involves finegrained clay. For medium and coarsegrained clay, if the content of grains in the clay is below 30%, it is acceptable to have a slightly larger plasticity index (liquid limit measured with 100g statocone). 8/151 (2) When clay cement is used as base layer, the maximal size of clay grain shall not exceed 40mm. The grain position of clay should fall within the range of the curves, which shall be smooth ones, in Fig. . The range of grain position corresponding to the curves in the figure is specified in Table ~2. The aggregates shall contain little or no clay with plasticity index. For secondclass highway, the mixture shall be prepared according to the lower limit group of the gradation range. (3) Materials suitable for use as clay cement base layer include: graded macadam, unscreened macadam, macadam clay, sand gravel clay, coal slack and various granular slag. Macadam includes rock macadam and broken slag. Table Range of grain position of aggregates suitable for cement stabilization (Base layer of highway secondclass and below) Mesh size (mm) Pass percent (%) 40 100 20 55～ 100 10 40～ 100 5 30～ 90 2 18～ 68 1 10～ 55 6～ 45 3～ 36 0～ 30 Screen size (mm) Fig. Range of grain position of aggregates suitable for cement stabilization (Base layer of ordinary highway) Pass percent (%) (weight) 9/151 For firstclass highway and speedway (1) When clay cement is used as subbase, the maximal size of aggregates shall not exceed 40mm. The grain position of aggregates suitable for cement stabilization should fall within the range indicated in Fig. , the curves of which shall be smooth ones, or should be in the range shown in Table ~3 (1 gradation). (2) When clay cement is used as base layer, the maximal size of aggregates shall not exceed 30mm. The grain position of aggregates shall fall within the range listed in Table ~3 (2 gradation). When cement is used to stabilize sand with uniform size, a small amount of clayey○ 1 or limestone clay with plasticity index less than 10 should be added into the sand, or some coal ash may be added. The ratio of addition can be determined in a way to allow the standard dry density of the mixture to be close to the maximal value, which is generally about 20%~40%. Note: ○1 Mild clay as described formerly The crushing resistance of macadam or gravel in the clay cement shall meet the following requirements: For highway secondclass or below, the crushing value of aggregates shall be no greater than 35%①。 For firstclass highway and speedway, the crushing value of aggregates shall be no greater than 30%. Note: ○1 For subbase of highway below secondclass, the crushing value can reach 40%. Clay with anic substance in excess of 2% shall not be stabilized solely with cement. In case such clay is to be used, it must first be treated with lime, and covered for a whole night before it is stabilized with cement. Clay with sulfate content in excess of % shall not be stabilized with cement. 10/151 Table Range of grain position of aggregates suitable for cement stabilization (Speedway and firstclass highway) No. 1 2 Pass perce。